1661416800

# SymbolicUtils.jl: Expression Rewriting and Simplification

SymbolicUtils.jl

SymbolicUtils.jl provides various utilities for symbolic computing. SymbolicUtils.jl is what one would use to build a Computer Algebra System (CAS). If you're looking for a complete CAS, similar to SymPy or Mathematica, see Symbolics.jl. If you want to build a crazy CAS for your weird Octonian algebras, you've come to the right place.

Symbols in SymbolicUtils carry type information. Operations on them propagate this information. A rule-based rewriting language can be used to find subexpressions that satisfy arbitrary conditions and apply arbitrary transformations on the matches. The library also contains a set of useful simplification rules for expressions of numeric symbols and numbers. These can be remixed and extended for special purposes.

If you are a Julia package develper in need of a rule rewriting system for your own types, have a look at the interfacing guide.

Go to the manual

SymbolicUtils.jl is on the general registry and can be added the usual way:

``````pkg> add SymbolicUtils
``````

or

``````julia> using Pkg; Pkg.add("SymbolicUtils")
``````

### "I don't want to read your manual, just show me some cool code"

``````julia> using SymbolicUtils

julia> SymbolicUtils.show_simplified[] = true

julia> @syms x::Real y::Real z::Complex f(::Number)::Real
(x, y, z, f(::Number)::Real)

julia> 2x^2 - y + x^2
(3 * (x ^ 2)) + (-1 * y)

julia> f(sin(x)^2 + cos(x)^2) + z
f(1) + z

julia> r = @rule sinh(im * ~x) => sin(~x)
sinh(im * ~x) => sin(~x)

julia> r(sinh(im * y))
sin(y)

julia> simplify(cos(y)^2 + sinh(im*y)^2, RuleSet([r]))
1
``````

Citations

• The pattern matcher is an adaption of the one by Gerald Jay Sussman (as seen in 6.945 at MIT), his use of symbolic programming in the book SICM inspired this package.
• Rewrite.jl and Simplify.jl by Harrison Grodin also inspired this package.

## Documentation

Author: JuliaSymbolics
Source Code: https://github.com/JuliaSymbolics/SymbolicUtils.jl

1625631360

## How to Upload and Store Images in MySQL using Node.js and Express

Today we are going to explore the basic usage of Express-FileUpload. In addition to this, I will show you how you can save/update a user record with a profile image that you can upload.

Chapters:
0:00 Introduction:
1:16 NPM Project Setup
3:54 Creating Express Server
5:51 Setting up Layouts & Routes
21:50 User Card
33:40 Database
52:05 Ending

1600693329

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We are available 24X7. Not just this, we also help with Garmin Express related needs, free Garmin Express Update, free updates for all Garmin devices, and lot more. Let us know your concern regarding Gramin Express, and we shall provide instant help!

#garmin express #garmin.com/express #garmin express update

1605177386

## How to Rate Limit an Express App

In this video, I’ll show you how to rate limit an Express app.

#rate limiting #expressjs #express #express framework #express rest api #node api tutorial

1661416800

## SymbolicUtils.jl: Expression Rewriting and Simplification

SymbolicUtils.jl

SymbolicUtils.jl provides various utilities for symbolic computing. SymbolicUtils.jl is what one would use to build a Computer Algebra System (CAS). If you're looking for a complete CAS, similar to SymPy or Mathematica, see Symbolics.jl. If you want to build a crazy CAS for your weird Octonian algebras, you've come to the right place.

Symbols in SymbolicUtils carry type information. Operations on them propagate this information. A rule-based rewriting language can be used to find subexpressions that satisfy arbitrary conditions and apply arbitrary transformations on the matches. The library also contains a set of useful simplification rules for expressions of numeric symbols and numbers. These can be remixed and extended for special purposes.

If you are a Julia package develper in need of a rule rewriting system for your own types, have a look at the interfacing guide.

Go to the manual

SymbolicUtils.jl is on the general registry and can be added the usual way:

``````pkg> add SymbolicUtils
``````

or

``````julia> using Pkg; Pkg.add("SymbolicUtils")
``````

### "I don't want to read your manual, just show me some cool code"

``````julia> using SymbolicUtils

julia> SymbolicUtils.show_simplified[] = true

julia> @syms x::Real y::Real z::Complex f(::Number)::Real
(x, y, z, f(::Number)::Real)

julia> 2x^2 - y + x^2
(3 * (x ^ 2)) + (-1 * y)

julia> f(sin(x)^2 + cos(x)^2) + z
f(1) + z

julia> r = @rule sinh(im * ~x) => sin(~x)
sinh(im * ~x) => sin(~x)

julia> r(sinh(im * y))
sin(y)

julia> simplify(cos(y)^2 + sinh(im*y)^2, RuleSet([r]))
1
``````

Citations

• The pattern matcher is an adaption of the one by Gerald Jay Sussman (as seen in 6.945 at MIT), his use of symbolic programming in the book SICM inspired this package.
• Rewrite.jl and Simplify.jl by Harrison Grodin also inspired this package.

## Documentation

Author: JuliaSymbolics
Source Code: https://github.com/JuliaSymbolics/SymbolicUtils.jl

1626725100

## Learn Express JS by building a Project - Installing Express

In this video series, we are going to learn Express JS by building a project. Express is a minimal and flexible Node.js web application framework that provides a robust set of features for web and mobile applications.

Along the way we are going to learn what is Express and how it works. Along with Express, we are also going to learn about other dependencies that are required for the backend. Finally, we will create an application that uses CRUD(create, read, update and delete) functionality.

However, in this video, we will learn how to install express js in your application and how to create a server for your application to run.

Get the entire code of this series here : https://github.com/Bishwahangdewan/Learn-Express-by-building-a-Project

#express #expressjs #nodejs

#nodejs #expressjs #express #installing express #js