10 Useful Resources To Access AI/ML Research

Every month, thousands of new research papers appear on the internet. Finding the right research papers for your research work or machine learning experiments is challenging.

Read more: https://analyticsindiamag.com/10-useful-resources-to-access-ai-ml-research/

#research #ml #ai

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Pdf2gerb: Perl Script Converts PDF Files to Gerber format

pdf2gerb

Perl script converts PDF files to Gerber format

Pdf2Gerb generates Gerber 274X photoplotting and Excellon drill files from PDFs of a PCB. Up to three PDFs are used: the top copper layer, the bottom copper layer (for 2-sided PCBs), and an optional silk screen layer. The PDFs can be created directly from any PDF drawing software, or a PDF print driver can be used to capture the Print output if the drawing software does not directly support output to PDF.

The general workflow is as follows:

1. Design the PCB using your favorite CAD or drawing software.
2. Print the top and bottom copper and top silk screen layers to a PDF file.
3. Run Pdf2Gerb on the PDFs to create Gerber and Excellon files.
4. Use a Gerber viewer to double-check the output against the original PCB design.
5. Make adjustments as needed.
6. Submit the files to a PCB manufacturer.

Please note that Pdf2Gerb does NOT perform DRC (Design Rule Checks), as these will vary according to individual PCB manufacturer conventions and capabilities. Also note that Pdf2Gerb is not perfect, so the output files must always be checked before submitting them. As of version 1.6, Pdf2Gerb supports most PCB elements, such as round and square pads, round holes, traces, SMD pads, ground planes, no-fill areas, and panelization. However, because it interprets the graphical output of a Print function, there are limitations in what it can recognize (or there may be bugs).

See docs/Pdf2Gerb.pdf for install/setup, config, usage, and other info.

---

pdf2gerb_cfg.pm

#Pdf2Gerb config settings:
#Put this file in same folder/directory as pdf2gerb.pl itself (global settings),
#or copy to another folder/directory with PDFs if you want PCB-specific settings.
#There is only one user of this file, so we don't need a custom package or namespace.
#NOTE: all constants defined in here will be added to main namespace.
#package pdf2gerb_cfg;

use strict; #trap undef vars (easier debug)
use warnings; #other useful info (easier debug)


##############################################################################################
#configurable settings:
#change values here instead of in main pfg2gerb.pl file

use constant WANT_COLORS => ($^O !~ m/Win/); #ANSI colors no worky on Windows? this must be set < first DebugPrint() call

#just a little warning; set realistic expectations:
#DebugPrint("${\(CYAN)}Pdf2Gerb.pl ${\(VERSION)}, $^O O/S\n${\(YELLOW)}${\(BOLD)}${\(ITALIC)}This is EXPERIMENTAL software.  \nGerber files MAY CONTAIN ERRORS.  Please CHECK them before fabrication!${\(RESET)}", 0); #if WANT_DEBUG

use constant METRIC => FALSE; #set to TRUE for metric units (only affect final numbers in output files, not internal arithmetic)
use constant APERTURE_LIMIT => 0; #34; #max #apertures to use; generate warnings if too many apertures are used (0 to not check)
use constant DRILL_FMT => '2.4'; #'2.3'; #'2.4' is the default for PCB fab; change to '2.3' for CNC

use constant WANT_DEBUG => 0; #10; #level of debug wanted; higher == more, lower == less, 0 == none
use constant GERBER_DEBUG => 0; #level of debug to include in Gerber file; DON'T USE FOR FABRICATION
use constant WANT_STREAMS => FALSE; #TRUE; #save decompressed streams to files (for debug)
use constant WANT_ALLINPUT => FALSE; #TRUE; #save entire input stream (for debug ONLY)

#DebugPrint(sprintf("${\(CYAN)}DEBUG: stdout %d, gerber %d, want streams? %d, all input? %d, O/S: $^O, Perl: $]${\(RESET)}\n", WANT_DEBUG, GERBER_DEBUG, WANT_STREAMS, WANT_ALLINPUT), 1);
#DebugPrint(sprintf("max int = %d, min int = %d\n", MAXINT, MININT), 1); 

#define standard trace and pad sizes to reduce scaling or PDF rendering errors:
#This avoids weird aperture settings and replaces them with more standardized values.
#(I'm not sure how photoplotters handle strange sizes).
#Fewer choices here gives more accurate mapping in the final Gerber files.
#units are in inches
use constant TOOL_SIZES => #add more as desired
(
#round or square pads (> 0) and drills (< 0):
    .010, -.001,  #tiny pads for SMD; dummy drill size (too small for practical use, but needed so StandardTool will use this entry)
    .031, -.014,  #used for vias
    .041, -.020,  #smallest non-filled plated hole
    .051, -.025,
    .056, -.029,  #useful for IC pins
    .070, -.033,
    .075, -.040,  #heavier leads
#    .090, -.043,  #NOTE: 600 dpi is not high enough resolution to reliably distinguish between .043" and .046", so choose 1 of the 2 here
    .100, -.046,
    .115, -.052,
    .130, -.061,
    .140, -.067,
    .150, -.079,
    .175, -.088,
    .190, -.093,
    .200, -.100,
    .220, -.110,
    .160, -.125,  #useful for mounting holes
#some additional pad sizes without holes (repeat a previous hole size if you just want the pad size):
    .090, -.040,  #want a .090 pad option, but use dummy hole size
    .065, -.040, #.065 x .065 rect pad
    .035, -.040, #.035 x .065 rect pad
#traces:
    .001,  #too thin for real traces; use only for board outlines
    .006,  #minimum real trace width; mainly used for text
    .008,  #mainly used for mid-sized text, not traces
    .010,  #minimum recommended trace width for low-current signals
    .012,
    .015,  #moderate low-voltage current
    .020,  #heavier trace for power, ground (even if a lighter one is adequate)
    .025,
    .030,  #heavy-current traces; be careful with these ones!
    .040,
    .050,
    .060,
    .080,
    .100,
    .120,
);
#Areas larger than the values below will be filled with parallel lines:
#This cuts down on the number of aperture sizes used.
#Set to 0 to always use an aperture or drill, regardless of size.
use constant { MAX_APERTURE => max((TOOL_SIZES)) + .004, MAX_DRILL => -min((TOOL_SIZES)) + .004 }; #max aperture and drill sizes (plus a little tolerance)
#DebugPrint(sprintf("using %d standard tool sizes: %s, max aper %.3f, max drill %.3f\n", scalar((TOOL_SIZES)), join(", ", (TOOL_SIZES)), MAX_APERTURE, MAX_DRILL), 1);

#NOTE: Compare the PDF to the original CAD file to check the accuracy of the PDF rendering and parsing!
#for example, the CAD software I used generated the following circles for holes:
#CAD hole size:   parsed PDF diameter:      error:
#  .014                .016                +.002
#  .020                .02267              +.00267
#  .025                .026                +.001
#  .029                .03167              +.00267
#  .033                .036                +.003
#  .040                .04267              +.00267
#This was usually ~ .002" - .003" too big compared to the hole as displayed in the CAD software.
#To compensate for PDF rendering errors (either during CAD Print function or PDF parsing logic), adjust the values below as needed.
#units are pixels; for example, a value of 2.4 at 600 dpi = .0004 inch, 2 at 600 dpi = .0033"
use constant
{
    HOLE_ADJUST => -0.004 * 600, #-2.6, #holes seemed to be slightly oversized (by .002" - .004"), so shrink them a little
    RNDPAD_ADJUST => -0.003 * 600, #-2, #-2.4, #round pads seemed to be slightly oversized, so shrink them a little
    SQRPAD_ADJUST => +0.001 * 600, #+.5, #square pads are sometimes too small by .00067, so bump them up a little
    RECTPAD_ADJUST => 0, #(pixels) rectangular pads seem to be okay? (not tested much)
    TRACE_ADJUST => 0, #(pixels) traces seemed to be okay?
    REDUCE_TOLERANCE => .001, #(inches) allow this much variation when reducing circles and rects
};

#Also, my CAD's Print function or the PDF print driver I used was a little off for circles, so define some additional adjustment values here:
#Values are added to X/Y coordinates; units are pixels; for example, a value of 1 at 600 dpi would be ~= .002 inch
use constant
{
    CIRCLE_ADJUST_MINX => 0,
    CIRCLE_ADJUST_MINY => -0.001 * 600, #-1, #circles were a little too high, so nudge them a little lower
    CIRCLE_ADJUST_MAXX => +0.001 * 600, #+1, #circles were a little too far to the left, so nudge them a little to the right
    CIRCLE_ADJUST_MAXY => 0,
    SUBST_CIRCLE_CLIPRECT => FALSE, #generate circle and substitute for clip rects (to compensate for the way some CAD software draws circles)
    WANT_CLIPRECT => TRUE, #FALSE, #AI doesn't need clip rect at all? should be on normally?
    RECT_COMPLETION => FALSE, #TRUE, #fill in 4th side of rect when 3 sides found
};

#allow .012 clearance around pads for solder mask:
#This value effectively adjusts pad sizes in the TOOL_SIZES list above (only for solder mask layers).
use constant SOLDER_MARGIN => +.012; #units are inches

#line join/cap styles:
use constant
{
    CAP_NONE => 0, #butt (none); line is exact length
    CAP_ROUND => 1, #round cap/join; line overhangs by a semi-circle at either end
    CAP_SQUARE => 2, #square cap/join; line overhangs by a half square on either end
    CAP_OVERRIDE => FALSE, #cap style overrides drawing logic
};
    
#number of elements in each shape type:
use constant
{
    RECT_SHAPELEN => 6, #x0, y0, x1, y1, count, "rect" (start, end corners)
    LINE_SHAPELEN => 6, #x0, y0, x1, y1, count, "line" (line seg)
    CURVE_SHAPELEN => 10, #xstart, ystart, x0, y0, x1, y1, xend, yend, count, "curve" (bezier 2 points)
    CIRCLE_SHAPELEN => 5, #x, y, 5, count, "circle" (center + radius)
};
#const my %SHAPELEN =
#Readonly my %SHAPELEN =>
our %SHAPELEN =
(
    rect => RECT_SHAPELEN,
    line => LINE_SHAPELEN,
    curve => CURVE_SHAPELEN,
    circle => CIRCLE_SHAPELEN,
);

#panelization:
#This will repeat the entire body the number of times indicated along the X or Y axes (files grow accordingly).
#Display elements that overhang PCB boundary can be squashed or left as-is (typically text or other silk screen markings).
#Set "overhangs" TRUE to allow overhangs, FALSE to truncate them.
#xpad and ypad allow margins to be added around outer edge of panelized PCB.
use constant PANELIZE => {'x' => 1, 'y' => 1, 'xpad' => 0, 'ypad' => 0, 'overhangs' => TRUE}; #number of times to repeat in X and Y directions

# Set this to 1 if you need TurboCAD support.
#$turboCAD = FALSE; #is this still needed as an option?

#CIRCAD pad generation uses an appropriate aperture, then moves it (stroke) "a little" - we use this to find pads and distinguish them from PCB holes. 
use constant PAD_STROKE => 0.3; #0.0005 * 600; #units are pixels
#convert very short traces to pads or holes:
use constant TRACE_MINLEN => .001; #units are inches
#use constant ALWAYS_XY => TRUE; #FALSE; #force XY even if X or Y doesn't change; NOTE: needs to be TRUE for all pads to show in FlatCAM and ViewPlot
use constant REMOVE_POLARITY => FALSE; #TRUE; #set to remove subtractive (negative) polarity; NOTE: must be FALSE for ground planes

#PDF uses "points", each point = 1/72 inch
#combined with a PDF scale factor of .12, this gives 600 dpi resolution (1/72 * .12 = 600 dpi)
use constant INCHES_PER_POINT => 1/72; #0.0138888889; #multiply point-size by this to get inches

# The precision used when computing a bezier curve. Higher numbers are more precise but slower (and generate larger files).
#$bezierPrecision = 100;
use constant BEZIER_PRECISION => 36; #100; #use const; reduced for faster rendering (mainly used for silk screen and thermal pads)

# Ground planes and silk screen or larger copper rectangles or circles are filled line-by-line using this resolution.
use constant FILL_WIDTH => .01; #fill at most 0.01 inch at a time

# The max number of characters to read into memory
use constant MAX_BYTES => 10 * M; #bumped up to 10 MB, use const

use constant DUP_DRILL1 => TRUE; #FALSE; #kludge: ViewPlot doesn't load drill files that are too small so duplicate first tool

my $runtime = time(); #Time::HiRes::gettimeofday(); #measure my execution time

print STDERR "Loaded config settings from '${\(__FILE__)}'.\n";
1; #last value must be truthful to indicate successful load


#############################################################################################
#junk/experiment:

#use Package::Constants;
#use Exporter qw(import); #https://perldoc.perl.org/Exporter.html

#my $caller = "pdf2gerb::";

#sub cfg
#{
#    my $proto = shift;
#    my $class = ref($proto) || $proto;
#    my $settings =
#    {
#        $WANT_DEBUG => 990, #10; #level of debug wanted; higher == more, lower == less, 0 == none
#    };
#    bless($settings, $class);
#    return $settings;
#}

#use constant HELLO => "hi there2"; #"main::HELLO" => "hi there";
#use constant GOODBYE => 14; #"main::GOODBYE" => 12;

#print STDERR "read cfg file\n";

#our @EXPORT_OK = Package::Constants->list(__PACKAGE__); #https://www.perlmonks.org/?node_id=1072691; NOTE: "_OK" skips short/common names

#print STDERR scalar(@EXPORT_OK) . " consts exported:\n";
#foreach(@EXPORT_OK) { print STDERR "$_\n"; }
#my $val = main::thing("xyz");
#print STDERR "caller gave me $val\n";
#foreach my $arg (@ARGV) { print STDERR "arg $arg\n"; }

---

Download Details:

Author: swannman
Source Code: https://github.com/swannman/pdf2gerb

License: GPL-3.0 license

#perl 

10 Useful Resources To Access AI/ML Research

Every month, thousands of new research papers appear on the internet. Finding the right research papers for your research work or machine learning experiments is challenging.

Read more: https://analyticsindiamag.com/10-useful-resources-to-access-ai-ml-research/

#research #ml #ai

Researchers Claim Inconsistent Model Performance In Most ML Research

The process of benchmarking is considered to be one of the most crucial assets for the progress of AI and machine learning research. The benchmark datasets are usually fixed sets of data, which are manually, semi-automatically as well as automatically generated to form a representative sample for these specific tasks to be solved by a model.

Recently, researchers from the Institute for Artificial Intelligence and Decision Support, Vienna claimed that the considerable part of metrics currently used to evaluate classification AI benchmark tasks might be inconsistent. It may result in a poor reflection in the performance of a classifier, especially when used with imbalanced datasets.

For the research, they analysed the present aspect of performance metrics that are based on data covering more than 3500 ML model performance results from a web-based open platform.

#developers corner #ai research benchmark #ai research papers #benchmark #benchmarking ai #bias in ml research #inconsistent benchmark

Making Sales More Efficient: Lead Qualification Using AI

If you were to ask any organization today, you would learn that they are all becoming reliant on Artificial Intelligence Solutions and using AI to digitally transform in order to bring their organizations into the new age. AI is no longer a new concept, instead, with the technological advancements that are being made in the realm of AI, it has become a much-needed business facet.

AI has become easier to use and implement than ever before, and every business is applying AI solutions to their processes. Organizations have begun to base their digital transformation strategies around AI and the way in which they conduct their business. One of these business processes that AI has helped transform is lead qualifications.

#ai-solutions-development #artificial-intelligence #future-of-artificial-intellige #ai #ai-applications #ai-trends #future-of-ai #ai-revolution

The Most Commonly Used Data Structures in Python

In any programming language, we need to deal with data.  Now, one of the most fundamental things that we need to work with the data is to store, manage, and access it efficiently in an organized way so it can be utilized whenever required for our purposes. Data Structures are used to take care of all our needs.

What are Data Structures?

Data Structures are fundamental building blocks of a programming language. It aims to provide a systematic approach to fulfill all the requirements mentioned previously in the article. The data structures in Python are List, Tuple, Dictionary, and Set. They are regarded as implicit or built-in Data Structures in Python. We can use these data structures and apply numerous methods to them to manage, relate, manipulate and utilize our data.

We also have custom Data Structures that are user-defined namely Stack, Queue, Tree, Linked List, and Graph. They allow users to have full control over their functionality and use them for advanced programming purposes. However, we will be focussing on the built-in Data Structures for this article.

Implicit Data Structures Python

LIST

Lists help us to store our data sequentially with multiple data types. They are comparable to arrays with the exception that they can store different data types like strings and numbers at the same time. Every item or element in a list has an assigned index. Since Python uses 0-based indexing, the first element has an index of 0 and the counting goes on. The last element of a list starts with -1 which can be used to access the elements from the last to the first. To create a list we have to write the items inside the square brackets.

One of the most important things to remember about lists is that they are Mutable. This simply means that we can change an element in a list by accessing it directly as part of the assignment statement using the indexing operator.  We can also perform operations on our list to get desired output. Let’s go through the code to gain a better understanding of list and list operations.

1. Creating a List

#creating the list
my_list = ['p', 'r', 'o', 'b', 'e']
print(my_list)

Output

['p', 'r', 'o', 'b', 'e']

2. Accessing items from the List

#accessing the list 
 
#accessing the first item of the list
my_list[0]

Output

'p'

#accessing the third item of the list
my_list[2]

'o'

3. Adding new items to the list

#adding item to the list
my_list + ['k']

Output

['p', 'r', 'o', 'b', 'e', 'k']

4. Removing Items

#removing item from the list
#Method 1:
 
#Deleting list items
my_list = ['p', 'r', 'o', 'b', 'l', 'e', 'm']
 
# delete one item
del my_list[2]
 
print(my_list)
 
# delete multiple items
del my_list[1:5]
 
print(my_list)

Output

['p', 'r', 'b', 'l', 'e', 'm']
['p', 'm']

#Method 2:
 
#with remove fucntion
my_list = ['p','r','o','k','l','y','m']
my_list.remove('p')
 
 
print(my_list)
 
#Method 3:
 
#with pop function
print(my_list.pop(1))
 
# Output: ['r', 'k', 'l', 'y', 'm']
print(my_list)

Output

['r', 'o', 'k', 'l', 'y', 'm']
o
['r', 'k', 'l', 'y', 'm']

5. Sorting List

#sorting of list in ascending order
 
my_list.sort()
print(my_list)

Output

['k', 'l', 'm', 'r', 'y']

#sorting of list in descending order
 
my_list.sort(reverse=True)
print(my_list)

Output

['y', 'r', 'm', 'l', 'k']

6. Finding the length of a List

#finding the length of list
 
len(my_list)

Output

5

TUPLE

Tuples are very similar to lists with a key difference that a tuple is IMMUTABLE, unlike a list. Once we create a tuple or have a tuple, we are not allowed to change the elements inside it. However, if we have an element inside a tuple, which is a list itself, only then we can access or change within that list. To create a tuple, we have to write the items inside the parenthesis. Like the lists, we have similar methods which can be used with tuples. Let’s go through some code snippets to understand using tuples.

1. Creating a Tuple

#creating of tuple
 
my_tuple = ("apple", "banana", "guava")
print(my_tuple)

Output

('apple', 'banana', 'guava')

2. Accessing items from a Tuple

#accessing first element in tuple
 
my_tuple[1]

Output

'banana'

3. Length of a Tuple

#for finding the lenght of tuple
 
len(my_tuple)

Output

3

4. Converting a Tuple to List

#converting tuple into a list
 
my_tuple_list = list(my_tuple)
type(my_tuple_list)

Output

list

5. Reversing a Tuple

#Reversing a tuple
 
tuple(sorted(my_tuple, reverse=True)) 

Output

('guava', 'banana', 'apple')

6. Sorting a Tuple

#sorting tuple in ascending order
 
tuple(sorted(my_tuple)) 

Output

('apple', 'banana', 'guava')

7. Removing elements from Tuple

For removing elements from the tuple, we first converted the tuple into a list as we did in one of our methods above( Point No. 4) then followed the same process of the list, and explicitly removed an entire tuple, just using the del statement.

DICTIONARY

Dictionary is a collection which simply means that it is used to store a value with some key and extract the value given the key. We can think of it as a set of key: value pairs and every key in a dictionary is supposed to be unique so that we can access the corresponding values accordingly.

A dictionary is denoted by the use of curly braces { } containing the key: value pairs. Each of the pairs in a dictionary is comma separated. The elements in a dictionary are un-ordered the sequence does not matter while we are accessing or storing them.

They are MUTABLE which means that we can add, delete or update elements in a dictionary. Here are some code examples to get a better understanding of a dictionary in python.

An important point to note is that we can’t use a mutable object as a key in the dictionary. So, a list is not allowed as a key in the dictionary.

1. Creating a Dictionary

#creating a dictionary
 
my_dict = {
    1:'Delhi',
    2:'Patna',
    3:'Bangalore'
}
print(my_dict)

Output

{1: 'Delhi', 2: 'Patna', 3: 'Bangalore'}

Here, integers are the keys of the dictionary and the city name associated with integers are the values of the dictionary.

2. Accessing items from a Dictionary

#access an item
 
print(my_dict[1])

Output

'Delhi'

3. Length of a Dictionary

#length of the dictionary
 
len(my_dict)

Output

3

4. Sorting a Dictionary

#sorting based on the key 
 
Print(sorted(my_dict.items()))
 
 
#sorting based on the values of dictionary
 
print(sorted(my_dict.values()))

Output

[(1, 'Delhi'), (2, 'Bangalore'), (3, 'Patna')]
 
['Bangalore', 'Delhi', 'Patna']

5. Adding elements in Dictionary

#adding a new item in dictionary 
 
my_dict[4] = 'Lucknow'
print(my_dict)

Output

{1: 'Delhi', 2: 'Patna', 3: 'Bangalore', 4: 'Lucknow'}

6. Removing elements from Dictionary

#for deleting an item from dict using the specific key
 
my_dict.pop(4)
print(my_dict)
 
#for deleting last item from the list
 
my_dict.popitem()
 
#for clearing the dictionary
 
my_dict.clear()
print(my_dict)

Output

{1: 'Delhi', 2: 'Patna', 3: 'Bangalore'}
(3, 'Bangalore')
{}

SET

Set is another data type in python which is an unordered collection with no duplicate elements. Common use cases for a set are to remove duplicate values and to perform membership testing. Curly braces or the set() function can be used to create sets. One thing to keep in mind is that while creating an empty set, we have to use set(), and not { }. The latter creates an empty dictionary.

Here are some code examples to get a better understanding of sets in python.

1. Creating a Set

#creating set
 
my_set = {"apple", "mango", "strawberry", "apple"}
print(my_set)

Output

{'apple', 'strawberry', 'mango'}

2. Accessing items from a Set

#to test for an element inside the set
 
"apple" in my_set

Output

True

3. Length of a Set

print(len(my_set))

Output

3

4. Sorting a Set

print(sorted(my_set))

Output

['apple', 'mango', 'strawberry']

5. Adding elements in Set

my_set.add("guava")
print(my_set)

Output

{'apple', 'guava', 'mango', 'strawberry'}

6. Removing elements from Set

my_set.remove("mango")
print(my_set)

Output

{'apple', 'guava', 'strawberry'}

Conclusion

In this article, we went through the most commonly used data structures in python and also saw various methods associated with them.

Link: https://www.askpython.com/python/data

#python #datastructures