# Matlab

MATLAB is a high-level language and interactive programming environment for numerical computation and visualization developed by MathWorks.

1678710180

## ARTE is a Matlab toolbox focussed on robotic manipulators, both serial and parallel mechanisms are included.

The main features of ARTE are:

• Simulate any industrial robot within a Matlab environment.
• Represent a visualize the Denavit-Hartenberg's system on the robot.
• 3D graphics of a great number of industrial robots are available.
• You can plot and observe the position, velocity and acceleration of the joint coordinates of the robot when a movement is performed.
• Also, the torques and forces at each joint can be plotted.
• A GUI teaching pendant is available to move and program the robots.
• The robots can be programmed and simulated ABB RAPID language. A step by step simulation of the programs can be carried out within the Matlab's editor and debugger.
• A Matlab to RAPID interpreter is included that allows to program the real robot using your Matlab code.
• New robot models can be easily included.
• Practical exercises are provided.

INSTALL copy the directory containing all the .m files to a directory named arte3.3.X. To initialize the library, inside Matlab you should be placed in the directory where the library is installed:

``````#!matlab

>> pwd
ans =
/Users/arturo/Desktop/arte3.2.X
``````

Next, in the Matlab command prompt type:

``````#!matlab

>> init_lib
``````

To view all functions and demos type:

``````#!matlab

>>help Contents
``````

If you want to have a fast view of the main capabilities of the library, type:

``````#!matlab

>> demos
``````

PRACTICAL EXERCISES WITH THE LIBRARY http://arvc.umh.es/arte/index_en.html#practicals

LIST OF ROBOTS SUPPORTED BY THE LIBRARY http://arvc.umh.es/arte/supported_robots.htmle/supported_robots.html}

Author: 4rtur1t0
Source Code: https://github.com/4rtur1t0/ARTE

1676495520

## 〰️ hctsa 〰️: highly comparative time-series analysis

hctsa is a Matlab software package for running highly comparative time-series analysis. It extracts thousands of time-series features from a collection of univariate time series and includes a range of tools for visualizing and analyzing the resulting time-series feature matrix, including:

1. Normalizing and clustering time-series data;
2. Producing low-dimensional representations of time-series data;
3. Identifying and interpreting discriminating features between different classes of time series; and
4. Fitting and evaluating multivariate classification models.

## Installation

For users familiar with git (recommended), please make a fork of the repo and then clone it to your local machine. To update, after setting an upstream remote (`git remote add upstream git://github.com/benfulcher/hctsa.git`) you can use `git pull upstream main`.

Once downloaded, you can install hctsa by running the `install.m` script (see docs for details).

## Documentation and Wiki 📖

Comprehensive documentation for hctsa, from getting started through to more advanced analyses is on GitBook.

There is also alot of additional information on the wiki, including:

• 👉 Information about alternative feature sets (including the much faster catch22), and information about other time-series packages available in R, python, and Julia.
• 〰️ The accompanying time-series data archive for this project, CompEngine.
• 💾 Downloadable hctsa feature matrices from time-series datasets with example workflows.
• 💻 Resources for distributing an hctsa computation on a computing cluster.
• 📕 A list of publications that have used hctsa to address different research questions.
• 💁 Frequently asked questions about hctsa and related feature-based time-series analyses.

## Acknowledgement 👍

If you use this software, please read and cite these open-access articles:

Feedback, as email, GitHub issues or pull requests, is much appreciated.

For commercial use of hctsa, including licensing and consulting, contact Engine Analytics.

## External packages and dependencies

Many features in hctsa rely on external packages and Matlab toolboxes. In the case that some of them are unavailable, hctsa can still be used, but only a reduced set of time-series features will be computed.

hctsa uses the following Matlab Add-On Toolboxes: Statistics and Machine Learning, Signal Processing, Curve Fitting, System Identification, Wavelet, and Econometrics.

The following external time-series analysis code packages are provided with the software (in the `Toolboxes` directory), and are used by our main feature-extraction algorithms to compute meaningful structural features from time series:

## Acknowledgements 👋

Many thanks go to Romesh Abeysuriya for helping with the mySQL database set-up and install scripts, and Santi Villalba for lots of helpful feedback and advice on the software.

Feel free to email me for advice on applications of hctsa 🤓

Author: Benfulcher
Source Code: https://github.com/benfulcher/hctsa

1669818274

## MATLAB for Beginners - Crash Course

Learn the fundametnals of MATLAB in this tutorial for engineers, scientists, and students. MATLAB is a programming language and software suite used for data analysis, scientific computing, and visualization that is widely used in academia and industry.

⭐️ Contents ⭐️
⌨️(0:00:00) Intro
⌨️(0:00:19) MATLAB IDE
⌨️(0:01:33) Variables & Arithmetic
⌨️(0:14:19) Matrices, Arrays, & Linear Algebra
⌨️(0:24:54) The Index
⌨️(0:31:16) Example 1 - Equations
⌨️(0:45:09) Anonymous Functions
⌨️(0:47:57) Example 2 - Plotting
⌨️(1:05:29) Example 3 - Logic
⌨️(1:20:24) Example 4 - Random & Loops
⌨️(1:26:07) Sections
⌨️(1:28:20) For Loops
⌨️(1:40:09) Calculation Time
⌨️(1:42:57) Naming Conventions
⌨️(1:45:09) File Naming
⌨️(1:45:54) While Loop
⌨️(1:50:16) Custom Function
⌨️(1:56:47) Have a good one ;)

#matlab

1661778507

## Julia-D4M

A Dynamic Distributed Dimensional Data Model(D4M) module for Julia. D4M was developed in MATLAB by Dr Jeremy Kepner and his team at Lincoln Labs. The goal is to implement D4M in a native Julia method. As a course project in Numeric Computation with Julia, various parts of this implementation has been completed and compared with the original matlab in performance. In the matrix performance example folder (testing performance in matrix like operations such as add and multiply), this implementation has achieved on par if not significant speed up (10x). This is thanks to the effectiveness of Julia base in comparision to Matlab.

The D4M Project Page: http://www.mit.edu/~kepner/D4M/

Current Status: (v0.5) - End of course project

• Printtable tabular
• Basic and advanced Assoc method of indexing
• All methods of construction Assoc implemented
• Implemented 1Intro/1AssocIntro and 3Scaling/3MatrixPerformance example folders and dependency.

Next Version: (v0.6) [Mid Feburary]

• Implement 1Intro/2EdgeArt and 2Apps/1EntityAnalysis example folders and dependency.
• Add interfaces to Julia's native DataFrame, allowing user to transfer data back and forth from JuliaStats

Author: Achen12
Source Code: https://github.com/achen12/D4M.jl

1659955626

## Moonwalk.jl: A Partial MATLAB to Julia Compiler

Moonwalk.jl

This is meant to be a partial MATLAB to Julia compiler, just to ease the transition of libraries.

Run with `./run_moonwalk.jl matlab_file.m`.

## Assumptions

1. Valid Matlab
2. No empty switch statements

## Testing

Run `./MoonwalkTest.jl` to run the test suite, or input specific numbers to run specific test cases (in the samples folder).

Author: Diogo149
Source Code: https://github.com/diogo149/Moonwalk.jl

1659948000

## MATLAB

The `MATLAB.jl` package provides an interface for using MATLAB® from Julia using the MATLAB C api. In other words, this package allows users to call MATLAB functions within Julia, thus making it easy to interoperate with MATLAB from the Julia language.

You cannot use `MATLAB.jl` without having purchased and installed a copy of MATLAB® from MathWorks. This package is available free of charge and in no way replaces or alters any functionality of MathWorks's MATLAB product.

## Overview

This package is composed of two aspects:

Creating and manipulating mxArrays (the data structure that MATLAB used to represent arrays and other kinds of data)

Communicating with MATLAB engine sessions

Warning:

MATLAB string arrays are not supported, and will throw an error exception. This also applies if they are nested within a MATLAB struct. This is a limitation of the MATLAB C api. The MATLAB function `convertContainedStringsToChars` may be used to facilitate conversion to a compatible format for use with `MATLAB.jl`.

Threading is also not supported within Julia when using the MATLAB.jl library.

## Installation

Important: The procedure to setup this package consists of the following steps.

By default, `MATLAB.jl` uses the MATLAB installation with the greatest version number. To specify that a specific MATLAB installation should be used, set the environment variable `MATLAB_ROOT`.

### Windows

For Matlab R2020a onwards, you should be able to go directly to step 2. If you encounter issues, run `matlab -batch "comserver('register')"` in the command prompt. For earlier versions of Matlab, start a command prompt as an administrator and enter `matlab /regserver`.

From Julia run: `Pkg.add("MATLAB")`

### Linux

Make sure `matlab` is in executable path.

Make sure `csh` is installed. (Note: MATLAB for Linux relies on `csh` to open an engine session.)

To install `csh` in Debian/Ubuntu/Linux Mint, you may type in the following command in terminal:

``sudo apt-get install csh``

From Julia run: `Pkg.add("MATLAB")`

### Mac OS X

Ensure that MATLAB is installed in `/Applications` (for example, if you are using MATLAB R2012b, you may add the following command to `.profile`: `export MATLAB_HOME=/Applications/MATLAB_R2012b.app`).

From Julia run: `Pkg.add("MATLAB")`

## Usage

### MxArray class

An instance of `MxArray` encapsulates a MATLAB variable. This package provides a series of functions to manipulate such instances.

#### Create MATLAB variables in Julia

One can use the function `mxarray` to create MATLAB variables (of type `MxArray`), as follows

``````mxarray(Float64, n)   # creates an n-by-1 MATLAB zero array of double valued type
mxarray(Int32, m, n)  # creates an m-by-n MATLAB zero array of int32 valued type
mxarray(Bool, m, n)   # creates a MATLAB logical array of size m-by-n

mxarray(Float64, (n1, n2, n3))  # creates a MATLAB array of size n1-by-n2-by-n3

mxcellarray(m, n)        # creates a MATLAB cell array
mxstruct("a", "b", "c")  # creates a MATLAB struct with given fields
``````

You may also convert a Julia variable to MATLAB variable

``````a = rand(m, n)

x = mxarray(a)     # converts a to a MATLAB array
x = mxarray(1.2)   # converts a scalar 1.2 to a MATLAB variable

a = sprand(m, n, 0.1)
x = mxarray(a)     # converts a sparse matrix to a MATLAB sparse matrix

x = mxarray("abc") # converts a string to a MATLAB char array

x = mxarray(["a", 1, 2.3])  # converts a Julia array to a MATLAB cell array

x = mxarray(Dict("a"=>1, "b"=>"string", "c"=>[1,2,3])) # converts a Julia dictionary to a MATLAB struct
``````

The function `mxarray` can also convert a compound type to a Julia struct:

``````struct S
x::Float64
y::Vector{Int32}
z::Bool
end

s = S(1.2, Int32[1, 2], false)

x = mxarray(s)   # creates a MATLAB struct with three fields: x, y, z
xc = mxarray([s, s])  # creates a MATLAB cell array, each cell is a struct.
xs = mxstructarray([s, s])  # creates a MATLAB array of structs
``````

Note: For safety, the conversation between MATLAB and Julia variables uses deep copy.

When you finish using a MATLAB variable, you may call `delete` to free the memory. But this is optional, it will be deleted when reclaimed by the garbage collector.

``````delete(x)
``````

Note: if you put a MATLAB variable `x` to MATLAB engine session, then the MATLAB engine will take over the management of its life cylce, and you don't have to delete it explicitly.

#### Access MATLAB variables

You may access attributes and data of a MATLAB variable through the functions provided by this package.

``````# suppose x is of type MxArray
nrows(x)    # returns number of rows in x
ncols(x)    # returns number of columns in x
nelems(x)   # returns number of elements in x
ndims(x)    # returns number of dimensions in x
size(x)     # returns the size of x as a tuple
size(x, d)  # returns the size of x along a specific dimension

eltype(x)   # returns element type of x (in Julia Type)
elsize(x)   # return number of bytes per element

data_ptr(x)   # returns pointer to data (in Ptr{T}), where T is eltype(x)

# suppose s is a MATLAB struct
mxnfields(s)    # returns the number of fields in struct s
``````

You may also make tests on a MATLAB variable.

``````is_double(x)   # returns whether x is a double array
is_sparse(x)   # returns whether x is sparse
is_complex(x)  # returns whether x is complex
is_cell(x)     # returns whether x is a cell array
is_struct(x)   # returns whether x is a struct
is_empty(x)    # returns whether x is empty

...            # there are many more there
``````

#### Convert MATLAB variables to Julia

``````a = jarray(x)   # converts x to a Julia array
a = jvector(x)  # converts x to a Julia vector (1D array) when x is a vector
a = jscalar(x)  # converts x to a Julia scalar
a = jmatrix(x)  # converts x to a Julia matrix
a = jstring(x)  # converts x to a Julia string
a = jdict(x)    # converts a MATLAB struct to a Julia dictionary (using fieldnames as keys)

a = jvalue(x)  # converts x to a Julia value in default manner
``````

This package provides functions to manipulate MATLAB's mat files:

``````mf = MatFile(filename, mode)    # opens a MAT file using a specific mode, and returns a handle
mf = MatFile(filename)          # opens a MAT file for reading, equivalent to MatFile(filename, "r")
close(mf)                       # closes a MAT file.

get_mvariable(mf, name)   # gets a variable and returns an mxArray
get_variable(mf, name)    # gets a variable, but converts it to a Julia value using `jvalue`

put_variable(mf, name, v)   # puts a variable v to the MAT file
# v can be either an MxArray instance or normal variable
# If v is not an MxArray, it will be converted using `mxarray`

put_variables(mf; name1=v1, name2=v2, ...)  # put multiple variables using keyword arguments

variable_names(mf)   # get a vector of all variable names in a MAT file
``````

There are also convenient functions that can get/put all variables in one call:

``````read_matfile(filename)    # returns a dictionary that maps each variable name
# to an MxArray instance

write_matfile(filename; name1=v1, name2=v2, ...)  # writes all variables given in the
# keyword argument list to a MAT file
``````

Both `read_matfile` and `write_matfile` will close the MAT file handle before returning.

Examples:

``````struct S
x::Float64
y::Bool
z::Vector{Float64}
end

write_matfile("test.mat";
a = Int32[1 2 3; 4 5 6],
b = [1.2, 3.4, 5.6, 7.8],
c = [[0.0, 1.0], [1.0, 2.0], [1.0, 2.0, 3.0]],
d = Dict("name"=>"MATLAB", "score"=>100.0),
s = "abcde",
ss = [S(1.0, true, [1., 2.]), S(2.0, false, [3., 4.])] )
``````

This example will create a MAT file called `test.mat`, which contains six MATLAB variables:

• `a`: a 2-by-3 int32 array
• `b`: a 4-by-1 double array
• `c`: a 3-by-1 cell array, each cell contains a double vector
• `d`: a struct with two fields: name and score
• `s`: a string (i.e. char array)
• `ss`: an array of structs with two elements, and three fields: x, y, and z.

### Use MATLAB Engine

#### Basic Use

To evaluate expressions in MATLAB, one may open a MATLAB engine session and communicate with it. There are three ways to call MATLAB from Julia:

• The `mat""` custom string literal allows you to write MATLAB syntax inside Julia and use Julia variables directly from MATLAB via interpolation
• The `eval_string` evaluate a string containing MATLAB expressions (typically used with the helper macros `@mget` and `@mput`
• The `mxcall` function calls a given MATLAB function and returns the result

In general, the `mat""` custom string literal is the preferred method to interact with the MATLAB engine.

Note: There can be multiple (reasonable) ways to convert a MATLAB variable to Julia array. For example, MATLAB represents a scalar using a 1-by-1 matrix. Here we have two choices in terms of converting such a matrix back to Julia: (1) convert to a scalar number, or (2) convert to a matrix of size 1-by-1.

The `mat""` custom string literal

Text inside the `mat""` custom string literal is in MATLAB syntax. Variables from Julia can be "interpolated" into MATLAB code by prefixing them with a dollar sign as you would interpolate them into an ordinary string.

``````using MATLAB

x = range(-10.0, stop=10.0, length=500)
mat"plot(\$x, sin(\$x))"  # evaluate a MATLAB function

y = range(2.0, stop=3.0, length=500)
mat"""
\$u = \$x + \$y
\$v = \$x - \$y
"""
@show u v               # u and v are accessible from Julia
``````

As with ordinary string literals, you can also interpolate whole Julia expressions, e.g. `mat"\$(x[1]) = \$(x[2]) + \$(binomial(5, 2))"`.

`eval_string`

You may also use the `eval_string` function to evaluate MATLAB code as follows

``````eval_string("a = sum([1,2,3])")
``````

The `eval_string` function also takes an optional argument that specifies which MATLAB session to evaluate the code in, e.g.

``````julia> s = MSession();
julia> eval_string(s, "a = sum([1,2,3])")
a =
6
``````

`mxcall`

You may also directly call a MATLAB function on Julia variables using `mxcall`:

``````x = -10.0:0.1:10.0
y = -10.0:0.1:10.0
xx, yy = mxcall(:meshgrid, 2, x, y)
``````

Note: Since MATLAB functions behavior depends on the number of outputs, you have to specify the number of output arguments in `mxcall` as the second argument.

`mxcall` puts the input arguments to the MATLAB workspace (using mangled names), evaluates the function call in MATLAB, and retrieves the variable from the MATLAB session. This function is mainly provided for convenience. However, you should keep in mind that it may incur considerable overhead due to the communication between MATLAB and Julia domain.

`@mget` and `@mput`

The macro `@mget` can be used to extract the value of a MATLAB variable into Julia

``````julia> mat"a = 6"
julia> @mget a
6.0
``````

The macro `@mput` can be used to translate a Julia variable into MATLAB

``````julia> x = [1,2,3]
julia> @mput x
julia> eval_string("y = sum(x)")
julia> @mget y
6.0
julia> @show y
a = 63.0
``````

#### Calling custom MATLAB function

If the MATLAB function is not in the current directory, we need to first add it to the MATLAB path before calling through Julia:

``````mat"addpath('/path/to/folder')"
val = mat"myfunction(\$arg1, \$arg2)"
``````

For example, if there is a MATLAB file located at `/path/to/folder` with contents:

``````function [r,u] = test(x, y)
r = x + y;
u = x - y;
end
``````

We can call this function as follows in Julia:

``````using MATLAB

x = range(-10.0, stop=10.0, length=500)
y = range(2.0, stop=3.0, length=500)

r, u = mxcall(:test,2,x,y)
``````

#### Viewing the MATLAB Session (Windows only)

To open an interactive window for the MATLAB session, use the command `show_msession()` and to hide the window, use `hide_msession()`. Warning: manually closing this window will result in an error or result in a segfault; it is advised that you only use the `hide_msession()` command to hide the interactive window.

Note that this feature only works on Windows.

``````# default
show_msession() # open the default MATLAB session interactive window
get_msession_visiblity() # get the session's visibility state
hide_msession() # hide the default MATLAB session interactive window

# similarily
s = MSession()
show_msession(s)
get_msession_visiblity(a)
hide_msession(s)
``````

#### Advanced use of MATLAB Engines

This package provides a series of functions for users to control the communication with MATLAB sessions.

Here is an example:

``````s1 = MSession()    # creates a MATLAB session
s2 = MSession(0)   # creates a MATLAB session without recording output

x = rand(3, 4)
put_variable(s1, :x, x)  # put x to session s1

y = rand(2, 3)
put_variable(s2, :y, y)  # put y to session s2

eval_string(s1, "r = sin(x)")  # evaluate sin(x) in session s1
eval_string(s2, "r = sin(y)")  # evaluate sin(y) in session s2

r1_mx = get_mvariable(s1, :r)  # get r from s1
r2_mx = get_mvariable(s2, :r)  # get r from s2

r1 = jarray(r1_mx)
r2 = jarray(r2_mx)

# ... do other stuff on r1 and r2

close(s1)  # close session s1
close(s2)  # close session s2``````

Author: JuliaInterop
Source Code: https://github.com/JuliaInterop/MATLAB.jl

1659940440

## MatlabCompat.jl

### Julia library aimed at simplifying conversion of legacy MATLAB/Octave code into Julia by providing functions similar to MATLAB/Octave

Julia is a new language with a dynamically growing community. It has a lot of syntax similarities to MATLAB/Octave with potential to build higher performance software. Because of this many developers in technical computing consider switching from MATLAB/Octave to Julia. This switch however maybe quite difficult in situations when one has a bulk amount of legacy code running on the daily basis. To simplify to transition of your legacy MATLAB/Octave code we have developed "MatlabCompat" a Julia library with a collection of functions rewritten from scratch under an open source MIT "Expat" license and some are named similarly to functions in MATLAB/Octave.

However, as a word of caution Julia is not MATLAB/Octave and was never meant to be. This library is not meant to substitute any commercial products (including those of Mathworks Inc.), nor is it meant to make Julia language closer to MATLAB/Octave. THe one and sole purpose of this library is to pave a way for enthusiast MATLB/Octave developers willing to engage with Julia open source language. For more information and help please refer to the Julia language homepage

## Developer

``````git clone https://github.com/MatlabCompat/MatlabCompat.jl && cd MatlabCompat.jl
julia -e 'Pkg.init(); run(`ln -s \$(pwd()) \$(Pkg.dir("MatlabCompat"))`); Pkg.pin("MatlabCompat"); Pkg.resolve()'
``````

On Windows you might want to use:

If you have any troubles simply remove the folder in your home folder and try again.

Afterwards check that `Pkg.status()` contains this package (with a master (dirty) side note)

### Dependencies

We use following Julia packages:

julia 0.4 Tk Images ImageView FixedPointNumbers MAT Color BinDeps ImageMagick

Also see REQUIRE file for details.

### Contribution guide can be found here

Author: MatlabCompa
Source Code: https://github.com/MatlabCompat/MatlabCompat.jl

1659932820

## MAT.jl

Read and write MATLAB files in Julia

This library can read MATLAB `.mat` files, both in the older v5/v6/v7 format, as well as the newer v7.3 format.

## Installation

This is installed using the standard tools of the package manager:

``````pkg> add MAT
``````

where you get the `pkg>` prompt by hitting `]` as the first character of the line. (Exit `pkg` mode by hitting backspace or Ctrl-C as the first character of the line.)

See also the requirements for the HDF5 module, used for "v7.3" files and for writing *.mat files.

## Usage

``````using MAT
``````

To read a single variable from a MAT file (compressed files are detected and handled automatically):

``````file = matopen("matfile.mat")
read(file, "varname") # note that this does NOT introduce a variable ``varname`` into scope
close(file)
``````

To write a variable to a MAT file:

``````file = matopen("matfile.mat", "w")
write(file, "varname", variable)
close(file)
``````

To read all variables from a MAT file as a Dict:

``````vars = matread("matfile.mat")
``````

To write a Dict to a MAT file, using its keys as variable names. The `compress` argument is optional, and compression is off by default:

``````matwrite("matfile.mat", Dict(
"myvar1" => 0,
"myvar2" => 1
); compress = true)
``````

To get a list of variable names in a MAT file:

``````file = matopen("matfile.mat")
varnames = keys(file)
close(file)
``````

To check for the presence of a variable name in a MAT file:

``````file = matopen("matfile.mat")
# something
end
close(file)
``````

## Caveats

• All files are written in MATLAB v7.3 format.
• MATLAB v4 files are not currently supported.

## Credits

The MAT_HDF5 module, which provides read/write support for MATLAB v7.3 files, was written primarily by Tim Holy. The MAT_v5 module, which provides read support for MATLAB v5/v6/v7 files, was written primarily by Simon Kornblith.

Author: JuliaIO
Source Code: https://github.com/JuliaIO/MAT.jl

1659925380

## `mexjulia`: embedding Julia in the MATLAB process.

Note: this project is effectively in hibernation as its author no longer has access to matlab.

## Prerequisites

`mexjulia` requires MATLAB (tested with R2016b) and Julia (>=v.0.6-dev) along with a C++ compiler configured to work with MATLAB's `mex` command, the last is required for building the `mexjulia` MEX function. You can check that a compiler is properly configured by executing:

``````>> mex -setup C++
``````

from the MATLAB command prompt.

## Configuration

Start MATLAB and navigate to the `mexjulia` directory. Once there, run:

``````>> jl.config
``````

You will be prompted to select a `julia` executable. The build process will:

1. use `julia` to determine build options,
2. build the `mexjulia` MEX function from source,
3. add the `mexjulia` directory to your MATLAB path.

Call `jl.config` any time you want to build against a different version of Julia. You can pass in the path to the desired Julia executable to build against if you don't want to be prompted to select one.

## Quick start

Use `jl.eval` to parse and evaluate MATLAB strings as Julia expressions:

``````>> jl.eval('2+2')

ans =

int64

4
``````

You can evaluate multiple expressions in a single call:

``````>> [s, c] = jl.eval('sin(pi/3)', 'cos(pi/3)')

s =

0.8660

c =

0.5000
``````

Julia's `STDOUT` and `STDERR` are redirected to the MATLAB console:

``````>> jl.eval('println("Hello, world!")');
Hello, world!
>> jl.eval('warn("Oh, no!")');
WARNING: Oh, no!
``````

One can avoid the parentheses and string quotes using `jleval` (a simple wrapper around `jl.eval`) and MATLAB's command syntax:

``````>> jleval 1 + 1

ans =

int64

2

>> jleval println("Hello, world!")
Hello, world!
``````

Use `jl.call` to call a Julia function specified by its name as a string:

``````>> jl.call('factorial', 10)

ans =

3628800
``````

`jl.call` marshals MATLAB data to/from Julia making certain default choices for doing so.

Load new Julia code by calling `jl.include`:

``````>> jl.include('my_own_julia_code.jl')
``````

Exercise more control over how data is marshaled between MATLAB and Julia by defining a Julia function with a "MEX-like" signature and invoking it with `jl.mex`:

``````>> jleval double_it(args::Vector{MxArray}) = [2*jvalue(arg) for arg in args]
>> a = rand(5,5)

a =

0.6443    0.9390    0.2077    0.1948    0.3111
0.3786    0.8759    0.3012    0.2259    0.9234
0.8116    0.5502    0.4709    0.1707    0.4302
0.5328    0.6225    0.2305    0.2277    0.1848
0.3507    0.5870    0.8443    0.4357    0.9049

>> jl.mex(1, 'double_it', a)

ans =

1.2886    1.8780    0.4155    0.3895    0.6222
0.7572    1.7519    0.6025    0.4518    1.8468
1.6232    1.1003    0.9418    0.3414    0.8604
1.0657    1.2450    0.4610    0.4553    0.3696
0.7015    1.1741    1.6886    0.8714    1.8098
``````

The first argument to `jl.mex` is the number of return values to expect. The second is the name of the function to be invoked. All remaining arguments are treated as function arguments. `jl.mex` expects the functions on which it is invoked to accept a single argument of type `Vector{MxArray}` and to return an iterable collection of values on which `mxarray` may be successfully invoked (e.g., a value of type `Vector{MxArray}`).

See `lmdif_test.m`, `lm.m`, and `lmdif.jl` for a more complex example that exposes `Optim.jl`'s Levenberg-Marquardt solver to MATLAB. It presents an example of a MATLAB function handle being passed to Julia and used as a callback. (The default marshaling wraps matlab function handles in an anonymous function.)

## Known Issues

• On Windows, if a julia is on the path it must be the one against which `mexjulia` is built.

Author: juliamatlab
Source Code: https://github.com/juliamatlab/mexjulia

1659767267

## Mex.jl: Embedding Julia in the MATLAB Process

In this tutorial, we'll learn about Mex.jl, embedding Julia in the MATLAB process using MATLAB's C++ Mex interface. This allows Julia functions to be called from MATLAB. This also allows (embedded) Julia to call MATLAB functions.

## Mex.jl

Embedding Julia in the MATLAB process

Mex.jl embeds Julia into the MATLAB process using MATLAB's C++ Mex interface. This allows Julia functions to be called from MATLAB. This also allows (embedded) Julia to call MATLAB functions.

## Prerequisites

`Mex.jl` requires MATLAB and Julia along with a C++ compiler configured to work with MATLAB's `mex` command, the last is required for building the `mexjulia` MEX function. You can check that a compiler is properly configured by executing:

``````>> mex -setup C++
``````

from the MATLAB command prompt.

NOTE: This project currently only supports Julia 1.5. Support for Julia 1.6 and greater will be possible when the changes resulting from https://github.com/JuliaLang/julia/issues/42411 are incorporated into the latest stable release of Julia.

## Installation

First ensure that the MATLAB.jl Julia package can be properly installed.

Then enter the package manager by typing `]` and then run the following:

``````pkg> add Mex
``````

The build process will:

1. use `julia` to determine build options,
2. build the `mexjulia` MEX function from source,
3. add the `mexjulia` directory to your MATLAB path.

By default, `Mex.jl` uses the MATLAB installation with the greatest version number. To specify that a specific MATLAB installation should be used, set the environment variable `MATLAB_ROOT`.

## Quick start

Use `jl.eval` to parse and evaluate MATLAB strings as Julia expressions:

``````>> jl.eval('2+2')

ans =

int64

4
``````

You can evaluate multiple expressions in a single call:

``````>> [s, c] = jl.eval('sin(pi/3), cos(pi/3)')

s =

0.8660

c =

0.5000
``````

Note that Julia's `STDOUT` and `STDERR` are not redirected to the MATLAB console. But if MATLAB is launched from the terminal they will appear there.

``````>> jl.eval('println("Hello, world!")');
>> jl.eval('@warn("Oh, no!")');
``````

One can avoid the parentheses and string quotes using `jleval` (a simple wrapper around `jl.eval`) and MATLAB's command syntax:

``````>> jleval 1 + 1

ans =

int64

2

>> jleval println("Hello, world!")
Hello, world!
``````

Use `jl.call` to call a Julia function specified by its name as a string:

``````>> jl.call('factorial', int64(10))

ans =

3628800
``````

Load new Julia code by calling `jl.include`:

``````>> jl.include('my_own_julia_code.jl')
``````

Exercise more control over how data is marshaled between MATLAB and Julia by defining a Julia function with a "MEX-like" signature and invoking it with `jl.mex`:

``````>> jleval import MATLAB
>> jleval double_it(args::Vector{MATLAB.MxArray}) = [2*MATLAB.jvalue(arg) for arg in args]
>> a = rand(5,5)

a =

0.6443    0.9390    0.2077    0.1948    0.3111
0.3786    0.8759    0.3012    0.2259    0.9234
0.8116    0.5502    0.4709    0.1707    0.4302
0.5328    0.6225    0.2305    0.2277    0.1848
0.3507    0.5870    0.8443    0.4357    0.9049

>> jl.mex('double_it', a)

ans =

1.2886    1.8780    0.4155    0.3895    0.6222
0.7572    1.7519    0.6025    0.4518    1.8468
1.6232    1.1003    0.9418    0.3414    0.8604
1.0657    1.2450    0.4610    0.4553    0.3696
0.7015    1.1741    1.6886    0.8714    1.8098
``````

The first argument to `jl.mex` is the name of the function to be invoked. All remaining arguments are treated as function arguments.

`jl.mex` expects the functions on which it is invoked to accept a single argument of type `Vector{MATLAB.MxArray}` and to return an iterable collection of values on which `MATLAB.mxarray` may be successfully invoked (e.g., a value of type `Vector{MATLAB.MxArray}`).

Additional usage examples may be found in the `examples` folder.

## Performance

To learn how to reduce the overhead associated with this package, see `performance.m` in the example folder.

Author: byuflowlab
Source Code: https://github.com/byuflowlab/Mex.jl
#julia #matlab

1659767019

## MATDaemon.jl: Calling Julia from MATLAB

In this tutorial, we'll learn about MATDaemon.jl, calling Julia from MATLAB. Calling MATLAB code from Julia via the C API has been supported for many years via MATLAB.jl

## MATDaemon.jl

Call Julia from MATLAB using a Julia daemon launched by `DaemonMode.jl`.

## Quickstart

Use the MATLAB function `jlcall.m` to call Julia from MATLAB:

``````>> jlcall('sort', {rand(2,5)}, struct('dims', int64(2)))

ans =

0.1270    0.2785    0.6324    0.8147    0.9575
0.0975    0.5469    0.9058    0.9134    0.9649
``````

The positional arguments passed to `jlcall.m` are:

1. The Julia function to call, given as a MATLAB `char` array. This can be any Julia expression which evaluates to a function. For example, `'a=2; b=3; x -> a*x+b'`. For convenience, the empty string `''` is interpreted as `'(args...; kwargs...) -> nothing'`, returning `nothing` for any inputs. Note: expressions are wrapped in a `let` block and evaluated in the global scope
2. Positional arguments, given as a MATLAB `cell` array. For example, `args = {arg1, arg2, ...}`
3. Keyword arguments, given as a MATLAB `struct`. For example, `kwargs = struct('key1', value1, 'key2', value2, ...)`

The first time `jlcall.m` is invoked:

1. `MATDaemon.jl` will be installed into a local Julia project, if one does not already exist. By default, a folder `.jlcall` is created in the same folder as `jlcall.m`
2. A Julia server will be started in the background using `DaemonMode.jl`

All subsequent calls to Julia are run on the Julia server. The server will be automatically killed when MATLAB exits.

### Restarting the Julia server

In the event that the Julia server reaches an undesired state, the server can be restarted by passing the `'restart'` flag with value `true`:

``````>> jlcall('', 'restart', true) % restarts the Julia server and returns nothing
``````

Similarly, one can shutdown the Julia server without restarting it:

``````>> jlcall('', 'shutdown', true) % shuts down the Julia server and returns nothing
``````

### Setting up the Julia environment

Before calling Julia functions, it may be necessary or convenient to first set up the Julia environment. For example, one may wish to activate a local project environment, run setup scripts, import modules for later use, or set the number of threads for running multithreaded code.

This setup can be conveniently executed at the start of your MATLAB script with a single call to `jlcall.m` as follows:

``````>> jlcall('', ...
'project', '/path/to/MyProject', ... % activate a local Julia Project
'setup', '/path/to/setup.jl', ... % run a setup script to load some custom Julia code
'modules', {'MyProject', 'LinearAlgebra', 'Statistics'}, ... % load a custom module and some modules from Base Julia
'restart', true ... % start a fresh Julia server environment
)
``````

See the corresponding sections below for more details about these flags.

The number of threads used by the Julia server can be set using the `'threads'` flag:

``````>> jlcall('() -> Threads.nthreads()', 'threads', 8, 'restart', true)

ans =

int64

8
``````

The default value for `'threads'` is `'auto'`, deferring to Julia to choose the number of threads.

Note: Julia cannot change the number of threads at runtime. In order for the `'threads'` flag to take effect, the server must be restarted.

Julia modules can be loaded and used:

``````>> jlcall('LinearAlgebra.norm', {[3.0; 4.0]}, 'modules', {'LinearAlgebra'})

ans =

5
``````

Note: modules are loaded using `import`, not `using`. Module symbols must therefore be fully qualified, e.g. `LinearAlgebra.norm` in the above example as opposed to `norm`.

### Persistent environments

By default, previously loaded Julia code is available on subsequent calls to `jlcall.m`. For example, following the above call to `LinearAlgebra.norm`, the `LinearAlgebra.det` function can be called without loading `LinearAlgebra` again:

``````>> jlcall('LinearAlgebra.det', {[1.0 2.0; 3.0 4.0]})

ans =

-2
``````

### Unique environments

Set the `'shared'` flag to `false` in order to evaluate each Julia call in a separate namespace on the Julia server:

``````% Restart the server, setting 'shared' to false
>> jlcall('LinearAlgebra.norm', {[3.0; 4.0]}, 'modules', {'LinearAlgebra'}, 'restart', true, 'shared', false)

ans =

5

% This call now errors, despite the above command loading the LinearAlgebra module, as LinearAlgebra.norm is evaluated in a new namespace
>> jlcall('LinearAlgebra.norm', {[3.0; 4.0]}, 'shared', false)
ERROR: LoadError: UndefVarError: LinearAlgebra not defined
Stacktrace:
...
``````

### Unique Julia instances

Instead of running Julia code on a persistent Julia server, unique Julia instances can be launched for each call to `jlcall.m` by passing the `'server'` flag with value `false`.

Note: this may cause significant overhead when repeatedly calling `jlcall.m` due to Julia package precompilation and loading:

``````>> tic; jlcall('x -> sum(abs2, x)', {1:5}, 'server', false); toc
Elapsed time is 4.181178 seconds. % call unique Julia instance

>> tic; jlcall('x -> sum(abs2, x)', {1:5}, 'restart', true); toc
Elapsed time is 5.046929 seconds. % re-initialize Julia server

>> tic; jlcall('x -> sum(abs2, x)', {1:5}); toc
Elapsed time is 0.267088 seconds. % call server; significantly faster
``````

Code from a local Julia project can be loaded and called:

``````>> jlcall('MyProject.my_function', args, kwargs, ...
'project', '/path/to/MyProject', ...
'modules', {'MyProject'})
``````

Note: the string passed via the `'project'` flag is simply forwarded to `Pkg.activate`; it is the user's responsibility to ensure that the project's dependencies have been installed.

Julia functions may require or return types which cannot be directly passed from or loaded into MATLAB. For example, suppose one would like to query `Base.VERSION`. Naively calling `jlcall('() -> Base.VERSION')` would fail, as `typeof(Base.VERSION)` is not a `String` but a `VersionNumber`.

One possible remedy is to define a wrapper function in a Julia script:

``````# setup.jl
julia_version() = string(Base.VERSION)
``````

Then, use the `'setup'` flag to pass the above script to `jlcall.m`:

``````>> jlcall('julia_version', 'setup', '/path/to/setup.jl')

ans =

'1.6.1'
``````

In this case, `jlcall('() -> string(Base.VERSION)')` would work just as well. In general, however, interfacing with complex Julia libraries using MATLAB types may be nontrivial, and the `'setup'` flag allows for the execution of arbitrary setup code.

Note: the setup script is loaded into the global scope using `include`; when using persistent environments, symbols defined in the setup script will be available on subsequent calls to `jlcall.m`.

### Handling Julia outputs

Output(s) from Julia are returned using the MATLAB `cell` array `varargout`, MATLAB's variable-length list of output arguments. A helper function `MATDaemon.matlabify` is used to convert Julia values into MATLAB-compatible values. Specifically, the following rules are used to populate `varargout` with the Julia output `y`:

1. If `y::Nothing`, then `varargout = {}` and no outputs are returned to MATLAB
2. If `y::Tuple`, then `length(y)` outputs are returned, with `varargout{i}` given by `matlabify(y[i])`
3. Otherwise, one output is returned with `varargout{1}` given by `matlabify(y)`

The following `matlabify` methods are defined by default:

``````matlabify(x) = x # default fallback
matlabify(::Union{Nothing, Missing}) = zeros(0,0) # equivalent to MATLAB's []
matlabify(x::Symbol) = string(x)
matlabify(xs::Tuple) = Any[matlabify(x) for x in xs] # matlabify values
matlabify(xs::Union{<:AbstractDict, <:NamedTuple, <:Base.Iterators.Pairs}) = Dict{String, Any}(string(k) => matlabify(v) for (k, v) in pairs(xs)) # convert keys to strings and matlabify values
``````

Note: MATLAB `cell` and `struct` types correspond to `Array{Any}` and `Dict{String, Any}` in Julia.

Conversion via `matlabify` can easily be extended to additional types. Returning to the example from the above section, we can define a `matlabify` method for `Base.VersionNumber`:

``````# setup.jl
MATDaemon.matlabify(v::Base.VersionNumber) = string(v)
``````

Now, the return type will be automatically converted:

``````>> jlcall('() -> Base.VERSION', 'setup', '/path/to/setup.jl')

ans =

'1.6.1'
``````

### Performance

MATLAB inputs and Julia ouputs are passed back and forth between MATLAB and the `DaemonMode.jl` server by writing to temporary `.mat` files. The location of these files can be configured with the `'infile'` and `'outfile'` flags, respectively. Pointing these files to a ram-backed file system is recommended when possible (for example, the `/tmp` folder on Linux is usually ram-backed), as read/write speed will likely improve. This is now the default; `'infile'` and `'outfile'` are created via the MATLAB `tempname` function (thanks to @mauro3 for this tip).

Nevertheless, this naturally leads to some overhead when calling Julia, particularly when the MATLAB inputs and/or Julia outputs have large memory footprints. It is therefore not recommended to use `jlcall.m` in performance critical loops.

## MATLAB and Julia version compatibility

This package has been tested on a variety of MATLAB versions. However, for some versions of Julia and MATLAB, supported versions of external libraries may clash. For example, running `jlcall.m` using Julia v1.6.1 and MATLAB R2015b gives the following error:

``````>> jlcall

ERROR: Unable to load dependent library ~/.local/julia-1.6.1/bin/../lib/julia/libjulia-internal.so.1

``````

This error results due to a clash of supported `libstdc++` versions, and does not occur when using e.g. Julia v1.5.4 with MATLAB R2015b, or Julia v1.6.1 with MATLAB R2020b.

If you encounter this issue, see the `Julia` and `MATLAB` documentation for information on mutually supported external libraries.

This repository contains utilities for parsing and running Julia code, passing MATLAB arguments to Julia, and retrieving Julia outputs from MATLAB.

The workhorse behind `MATDaemon.jl` and `jlcall.m` is `DaemonMode.jl` which is used to start a persistent Julia server in the background.

Author: jondeuce
Source Code: https://github.com/jondeuce/MATDaemon.jl
#julia #matlab

1658622780

## Machine Learning in MatLab/Octave

This repository contains MatLab/Octave examples of popular machine learning algorithms with code examples and mathematics behind them being explained.

The purpose of this repository was not to implement machine learning algorithms using 3rd party libraries or Octave/MatLab "one-liners" but rather to practice and to better understand the mathematics behind each algorithm. In most cases the explanations are based on this great machine learning course.

## Supervised Learning

In supervised learning we have a set of training data as an input and a set of labels or "correct answers" for each training set as an output. Then we're training our model (machine learning algorithm parameters) to map the input to the output correctly (to do correct prediction). The ultimate purpose is to find such model parameters that will successfully continue correct input→output mapping (predictions) even for new input examples.

### Regression

In regression problems we do real value predictions. Basically we try to draw a line/plane/n-dimensional plane along the training examples.

Usage examples: stock price forecast, sales analysis, dependency of any number, etc.

🤖 Linear Regression - example: house prices prediction.

### Classification

In classification problems we split input examples by certain characteristic.

Usage examples: spam-filters, language detection, finding similar documents, handwritten letters recognition, etc.

🤖 Logistic Regression - examples: microchip fitness detection, handwritten digits recognitions using one-vs-all approach.

## Unsupervised Learning

Unsupervised learning is a branch of machine learning that learns from test data that has not been labeled, classified or categorized. Instead of responding to feedback, unsupervised learning identifies commonalities in the data and reacts based on the presence or absence of such commonalities in each new piece of data.

### Clustering

In clustering problems we split the training examples by unknown characteristics. The algorithm itself decides what characteristic to use for splitting.

Usage examples: market segmentation, social networks analysis, organize computing clusters, astronomical data analysis, image compression, etc.

🤖 K-means algorithm - example: split data into three clusters.

### Anomaly Detection

Anomaly detection (also outlier detection) is the identification of rare items, events or observations which raise suspicions by differing significantly from the majority of the data.

Usage examples: intrusion detection, fraud detection, system health monitoring, removing anomalous data from the dataset etc.

🤖 Anomaly Detection using Gaussian distribution - example: detect overloaded server.

## Neural Network (NN)

The neural network itself isn't an algorithm, but rather a framework for many different machine learning algorithms to work together and process complex data inputs.

Usage examples: as a substitute of all other algorithms in general, image recognition, voice recognition, image processing (applying specific style), language translation, etc.

🤖 Neural Network: Multilayer Perceptron (MLP) - example: handwritten digits recognition.

## Machine Learning Map

The source of the following machine learning topics map is this wonderful blog post

## How to Use This Repository

### Install Octave or MatLab

This repository contains `*.m` scripts that are intended to be run in Octave or MatLab. Thus in order to launch demos you need either Octave or MatLab to be installed on you local machine. In case of MatLab you may also use its web-version.

### Run Demos

In order to run the demo of your choice you should move to the chosen folder (i.e. `neural-network`):

``````cd neural-network
``````

Launch Octave console:

``````octave
``````

Launch demo script from Octave console:

``````demo
``````

To see all demo variables you may launch:

``````whos
``````

To exit the demo you may launch:

``````exit
``````

Also be aware that demo scripts opens additional window with charts and other graphical information that is related to the running algorithm. You may find screenshots of the window that each demo will render for you on the dedicated README files for each machine learning algorithm.

Author: trekhleb
Source code: https://github.com/trekhleb/machine-learning-octave

1658615460

## Introduction

This Matlab package implements machine learning algorithms described in the great textbook: Pattern Recognition and Machine Learning by C. Bishop (PRML).

It is written purely in Matlab language. It is self-contained. There is no external dependency.

Note: this package requires Matlab R2016b or latter, since it utilizes a new Matlab syntax called Implicit expansion (a.k.a. broadcasting). It also requires Statistics Toolbox (for some simple random number generator) and Image Processing Toolbox (for reading image data).

## Design Goal

• Succinct: The code is extremely compact. Minimizing code length is a major goal. As a result, the core of the algorithms can be easily spotted.
• Efficient: Many tricks for speeding up Matlab code are applied (e.g. vectorization, matrix factorization, etc.). Usually, functions in this package are orders faster than Matlab builtin ones (e.g. kmeans).
• Robust: Many tricks for numerical stability are applied, such as computing probability in logrithm domain, square root matrix update to enforce matrix symmetry\PD, etc.
• Readable: The code is heavily commented. Corresponding formulas in PRML are annoted. Symbols are in sync with the book.
• Practical: The package is not only readable, but also meant to be easily used and modified to facilitate ML research. Many functions in this package are already widely used (see Matlab file exchange).

## Installation

``git clone https://github.com/PRML/PRMLT.git``

Run Matlab and navigate to the folder (~/PRMLT/), then run the init.m script.

Run some demos in ~/PRMLT/demo folder. Enjoy!

## FeedBack

If you find any bug or have any suggestion, please do file issues. I am graceful for any feedback and will do my best to improve this package.

## Contact

sth4nth at gmail dot com

Author: PRML
Source code: https://github.com/PRML/PRMLT

1658608080

## PRT: Pattern Recognition and Machine Learning in MATLAB

PRT: Pattern Recognition and Machine Learning in MATLAB

A free and permissively licensed object oriented approach to machine learning in MATLAB.

Machine learning and pattern recognition are everywhere. MATLAB is a high level interpreted language widely used throughout academia and engineering due to its ease of use and numerous available toolboxes. Currently available toolboxes for pattern recognition and machine learning in MATLAB are either costly or restrictively licensed. The PRT is a MIT licensed toolbox that provides access to a wide range of pattern recognition techniques in an easy to use unified framework. The PRT provides a suite of MATLAB commands and data-types to help you organize, visualize, process, cluster and classify your data. If you have data and need to make predictions based on your data, the PRT can help.

Author: covartech
Source code: https://github.com/covartech/PRT