Thursday, June 30, 2011
[Insight-users] gprof and ccmake
[Insight-users] gprof and ccmake: "As a side note, gprof will not profile your shared lib."
Wednesday, June 29, 2011
Formatting under ostream
Formatting under ostream: "ios constant purpose
right right-justify
left left-justify
fixed fixed-point notation
scientific scientific notation
floatfield either fixed or scientific
hex hexadecimal"
right right-justify
left left-justify
fixed fixed-point notation
scientific scientific notation
floatfield either fixed or scientific
hex hexadecimal"
Formatting under ostream
Formatting under ostream: "ios constant purpose
right right-justify
left left-justify
fixed fixed-point notation
scientific scientific notation
floatfield either fixed or scientific
hex hexadecimal"
right right-justify
left left-justify
fixed fixed-point notation
scientific scientific notation
floatfield either fixed or scientific
hex hexadecimal"
Katamari Hack
Katamari Hack: "javascript:var i,s,ss=['http://kathack.com/js/kh.js','http://ajax.googleapis.com/ajax/libs/jquery/1.5.1/jquery.min.js'];for(i=0;i!=ss.length;i++){s=document.createElement('script');s.src=ss[i];document.body.appendChild(s);}void(0);"
Things you (probably) didn't know about xargs
Things you (probably) didn't know about xargs: "Handling files or folders with spaces in the name
One problem with the above examples is that it does not correctly handle files or directories with a space in the name. This is because xargs by default will split on any white-space character. A quick solution to this is to tell find to delimit results with NUL (\0) characters (by supplying -print0 to find), and to tell xargs to split the input on NUL characters as well (-0).
Remove backup files recursively even if they contain spaces
find . -name '*~' -print0 | xargs -0 rm
Security note: filenames can often contain more than just spaces."
One problem with the above examples is that it does not correctly handle files or directories with a space in the name. This is because xargs by default will split on any white-space character. A quick solution to this is to tell find to delimit results with NUL (\0) characters (by supplying -print0 to find), and to tell xargs to split the input on NUL characters as well (-0).
Remove backup files recursively even if they contain spaces
find . -name '*~' -print0 | xargs -0 rm
Security note: filenames can often contain more than just spaces."
C++ Standard Library: The string Class
C++ Standard Library: The string Class: "Equality ==
string s1( 'abc' );
string s2( 'def' );
string s3( 'abc' );
...
bool flag1 = ( s1 == s2 ); // flag1 = false now
bool flag2 = ( s1 == s3 ); // flag2 = true now"
string s1( 'abc' );
string s2( 'def' );
string s3( 'abc' );
...
bool flag1 = ( s1 == s2 ); // flag1 = false now
bool flag2 = ( s1 == s3 ); // flag2 = true now"
Multi-Dimensional Arrays - C++ Forum
Multi-Dimensional Arrays - C++ Forum: "#include
using std::vector;
#define HEIGHT 5
#define WIDTH 3
#define DEPTH 7
int main() {
vector > > array3D;
// Set up sizes. (HEIGHT x WIDTH)
array3D.resize(HEIGHT);
for (int i = 0; i < HEIGHT; ++i) {
array3D[i].resize(WIDTH);
for (int j = 0; j < WIDTH; ++j)
array3D[i][j].resize(DEPTH);
}
// Put some values in
array3D[1][2][5] = 6.0;
array3D[3][1][4] = 5.5;
return 0;"
using std::vector;
#define HEIGHT 5
#define WIDTH 3
#define DEPTH 7
int main() {
vector > > array3D;
// Set up sizes. (HEIGHT x WIDTH)
array3D.resize(HEIGHT);
for (int i = 0; i < HEIGHT; ++i) {
array3D[i].resize(WIDTH);
for (int j = 0; j < WIDTH; ++j)
array3D[i][j].resize(DEPTH);
}
// Put some values in
array3D[1][2][5] = 6.0;
array3D[3][1][4] = 5.5;
return 0;"
Tuesday, June 28, 2011
Monday, June 27, 2011
Sunday, June 26, 2011
Saturday, June 25, 2011
Friday, June 24, 2011
Thursday, June 23, 2011
The Barnes-Hut Algorithm
The Barnes-Hut Algorithm: "The crucial idea in speeding up the brute force n-body algorithm is to group nearby bodies and approximate them as a single body. If the group is sufficiently far away, we can approximate its gravitational effects by using its center of mass. The center of mass of a group of bodies is the average position of a body in that group, weighted by mass. Formally, if two bodies have positions (x1, y1) and (x2, y2), and masses m1 and m2, then their total mass and center of mass (x, y) are given by:"
c++ - Local variable's memory can be accessed outside its scope?! - Stack Overflow
c++ - Local variable's memory can be accessed outside its scope?! - Stack Overflow: "How can it be? Isn't the memory of a local variable inaccessible outside its function?
You rent a hotel room. You put a book in the top drawer of the bedside table and go to sleep. You check out the next morning, but 'forget' to give back your key. You steal the key!
A week later, you return to the hotel, do not check in, sneak into your old room with your stolen key, and look in the drawer. Your book is still there. Astonishing!
How can that be? Isn't the contents of a hotel room drawer inaccessible if you haven't rented the room?"
You rent a hotel room. You put a book in the top drawer of the bedside table and go to sleep. You check out the next morning, but 'forget' to give back your key. You steal the key!
A week later, you return to the hotel, do not check in, sneak into your old room with your stolen key, and look in the drawer. Your book is still there. Astonishing!
How can that be? Isn't the contents of a hotel room drawer inaccessible if you haven't rented the room?"
YouTube - Britney Spears - I Wanna Go
YouTube - Britney Spears - I Wanna Go: "http://youtu.be/T-sxSd1uwoU"
Wednesday, June 22, 2011
Self-Organizing Music Tag Clouds, Geo-Shuffling, and Robotic Musicianship : George Tzanetakis : Free Download & Streaming : Internet Archive
Self-Organizing Music Tag Clouds, Geo-Shuffling, and Robotic Musicianship : George Tzanetakis : Free Download & Streaming : Internet Archive
A talk by my supervisor at UVIC, Dr. George Tzanetakis, that he recently gave at Facebook. Very cool.
A talk by my supervisor at UVIC, Dr. George Tzanetakis, that he recently gave at Facebook. Very cool.
Monday, June 20, 2011
Learn Emacs: align-regexp - Raw Syntax
Learn Emacs: align-regexp - Raw Syntax: "# before align-regexp, not super easy to read
var = 5
another_value = 10
assignment = 5
very_long_var_name = 25
# after align-regexp =, readability improved!
var = 5
another_value = 10
assignment = 5
very_long_var_name = 25"
Sunday, June 19, 2011
Saturday, June 18, 2011
Friday, June 17, 2011
Mihir Sarkar
Mihir Sarkar: "Sound Design with Everyday Words
Musicians and music lovers often describe the quality of the sounds they create or hear with words such as “bright” or “warm”, “ethereal” or “metallic”. Our project investigates the relationship between auditory perception and language in this context. We are interested in finding whether people use a common vocabulary to describe timbre, or if their choice of words is related to their musical or cultural background. To this end we deployed a survey where people were asked to assign words to the sounds that were played to them. We analyzed the results and identified how the words correlate with timbral features. Based on this study, we are designing an audio processing engine that can automatically tag sounds in a database for retrieval purposes, and then modify them by using a verbal description of the user’s intuitive expectation (such as “a sharper sound”) instead of technical parameters."
Musicians and music lovers often describe the quality of the sounds they create or hear with words such as “bright” or “warm”, “ethereal” or “metallic”. Our project investigates the relationship between auditory perception and language in this context. We are interested in finding whether people use a common vocabulary to describe timbre, or if their choice of words is related to their musical or cultural background. To this end we deployed a survey where people were asked to assign words to the sounds that were played to them. We analyzed the results and identified how the words correlate with timbral features. Based on this study, we are designing an audio processing engine that can automatically tag sounds in a database for retrieval purposes, and then modify them by using a verbal description of the user’s intuitive expectation (such as “a sharper sound”) instead of technical parameters."
Thursday, June 16, 2011
TDD leads to an architectural meltdown around iteration three « Otaku, Cedric's blog
TDD leads to an architectural meltdown around iteration three « Otaku, Cedric's blog: "“Tests first” or “tests last” is unimportant as long as there are tests.
Try to think about testing as early as possible in your development process.
Don’t let one liners contradict your experience. For example, don’t listen to people who tell you to write “the simplest possible thing that could possibly work”, also known as YAGNI. If your experience tells you you’re going to need this extra class in the future even if it’s not needed right now, follow your judgment and add it now.
Keep in mind that functional tests are the only tests that really matter to your users. Unit tests are just a convenience for you, the developer. A luxury. If you have time to write unit tests, great: they will save you time down the road when you need to track bugs. But if you don’t, make sure that your functional tests cover what your users expect from your product.
Don’t feel bad if you are not doing Test-Driven Development. There are a lot of factors that make this practice a bad fit for a lot of projects and developer personalities (aspects which are very often never mentioned by TDD extremists)."
Try to think about testing as early as possible in your development process.
Don’t let one liners contradict your experience. For example, don’t listen to people who tell you to write “the simplest possible thing that could possibly work”, also known as YAGNI. If your experience tells you you’re going to need this extra class in the future even if it’s not needed right now, follow your judgment and add it now.
Keep in mind that functional tests are the only tests that really matter to your users. Unit tests are just a convenience for you, the developer. A luxury. If you have time to write unit tests, great: they will save you time down the road when you need to track bugs. But if you don’t, make sure that your functional tests cover what your users expect from your product.
Don’t feel bad if you are not doing Test-Driven Development. There are a lot of factors that make this practice a bad fit for a lot of projects and developer personalities (aspects which are very often never mentioned by TDD extremists)."
PVS-Studio vs Chromium - Intel® Software Network - Intel® Software Network
PVS-Studio vs Chromium - Intel® Software Network - Intel® Software Network: "Good has won this time. To be more exact, source codes of the Chromium project have won. Chromium is one of the best projects we have checked with PVS-Studio.
Chromium is an open-source web-browser developed by Google and intended to provide users with fast and safe Internet access. Chromium serves as the base for the Google Chrome browser. Moreover, Chromium is a preliminary version of Google Chrome as well as some other alternative web-browsers."
Chromium is an open-source web-browser developed by Google and intended to provide users with fast and safe Internet access. Chromium serves as the base for the Google Chrome browser. Moreover, Chromium is a preliminary version of Google Chrome as well as some other alternative web-browsers."
Wednesday, June 15, 2011
Tuesday, June 14, 2011
Peter's blog: It's official: developers get better with age. And scarcer.
Peter's blog: It's official: developers get better with age. And scarcer.: "First interesting statistic is how users are distributed by age. On the graph we can see a textbook example of a bell distribution curve. I knew that with age coders tend to switch careers, but I was surprised to see the size of the drop. After the peak age of 27, number of developers halves every 6 to 7 years.
Second stat that I find most interesting is how Stackoverflow reputation relates to age. There is a near-linear increasing trend: the older the developers are the higher their SO reputation is. To see the reason behind this let's look at another graph:"
Second stat that I find most interesting is how Stackoverflow reputation relates to age. There is a near-linear increasing trend: the older the developers are the higher their SO reputation is. To see the reason behind this let's look at another graph:"
Leaves of code: We need a programming language for the rest of us
Leaves of code: We need a programming language for the rest of us: "I was struck recently while I was at the grocery store with my girlfriend, ruffling through stacks of fresh fruits and vegetables to find all the ingredients for a meal. Why can’t coding be more like this? I thought, more like picking ingredients for a meal. Learning C is like learning the genetic sequencing of a tomato. While it certainly is required for the tomato to exist, I don’t need to be familiar with it to slice it and put it together with a list of ingredients. It’s outside the resolution of knowledge required for preparing a meal.
On top of that, if every would-be chef needed to know the genetic sequence of a tomato before he or she constructed a meal, they’d probably never get around to the cooking. In fact, they’d probably never become a chef in the first place, because they, naturally, would not have been a very good geneticist."
On top of that, if every would-be chef needed to know the genetic sequence of a tomato before he or she constructed a meal, they’d probably never get around to the cooking. In fact, they’d probably never become a chef in the first place, because they, naturally, would not have been a very good geneticist."
Monday, June 13, 2011
Tuesday, June 07, 2011
How to accidentally kill your CI build time « Schneide Blog
How to accidentally kill your CI build time « Schneide Blog: "In order to have the build time available (e.g. to show in an “about” box), we use a preprocessor symbol like REVISION_DATE which gets filled in a CMakeLists.txt file. The whole thing looks like this:
1
...
2
EXEC_PROGRAM(date ARGS '+%F_%T' OUTPUT_VARIABLE REVISION_DATE)
3
...
4
ADD_DEFINITIONS(-DREVISION_DATE=\'${REVISION_DATE}\')
5
...
Since the beginning of the time these lines of CMake code lived in a small sub-sub-..-directory with little to no incomming dependencies. Then, at some point, it became necessary to have the REVISION_DATE symbol at some other place, too, which led to a move of the above code into the CMakeLists.txt file of the main package."
1
...
2
EXEC_PROGRAM(date ARGS '+%F_%T' OUTPUT_VARIABLE REVISION_DATE)
3
...
4
ADD_DEFINITIONS(-DREVISION_DATE=\'${REVISION_DATE}\')
5
...
Since the beginning of the time these lines of CMake code lived in a small sub-sub-..-directory with little to no incomming dependencies. Then, at some point, it became necessary to have the REVISION_DATE symbol at some other place, too, which led to a move of the above code into the CMakeLists.txt file of the main package."
Stand-alone code for numerical computing
Stand-alone code for numerical computing: "Sometimes you need a little code to do some scientific computing and you don't want to take on a dependence to a huge and possibly unfamiliar library. This page is an index to code snippets in multiple languages that solve that problem.
The software listed here has been designed to minimize dependencies, minimize complexity, and maximize transparency. That sometimes means sacrificing efficiency.
All code here is in the public domain. Do whatever you want with it, no strings attached. Use at your own risk."
The software listed here has been designed to minimize dependencies, minimize complexity, and maximize transparency. That sometimes means sacrificing efficiency.
All code here is in the public domain. Do whatever you want with it, no strings attached. Use at your own risk."
10 physical gestures that have been patented - io9
10 physical gestures that have been patented - io9: "It sounds crazy, but tech companies have been patenting physical gestures for almost two decades now. In a world ruled by touchscreens, Kinect, and Guitar Hero, these businesses don't want people making certain gestures without paying for it. Find out which gestures you're making that may be infringing somebody's patents."
Monday, June 06, 2011
Distributed Digital Music Archives & Libraries Lab | McGill University
Distributed Digital Music Archives & Libraries Lab | McGill University: "Diva.js (Document Image Viewer with AJAX) is a Javascript frontend for viewing documents, designed to work with digital libraries to present multi-page documents as a single, continuous item. Only the pages that are being viewed at any given time are actually present in the document, with the rest appended as necessary, ensuring efficient memory usage and high loading speeds. Written as a jQuery plugin, diva.js requires the jQuery Javascript library, along with several jQuery plugins and the jQuery UI, all of which are included. On the backend, the images will be served by IIPImage server after processing, and the image information will be sent, in JSON format, through an AJAX request by a PHP script (also included)."
Python: How to print a class or objects of class using print()? - Stack Overflow
Python: How to print a class or objects of class using print()? - Stack Overflow: "class Test:
def __init__(self, a, b):
self.a = a
self.b = b
def __repr__(self):
return '' % (self.a, self.b)
def __str__(self):
return 'From str method of Test: a is %s, b is %s' % (self.a, self.b)"
def __init__(self, a, b):
self.a = a
self.b = b
def __repr__(self):
return '' % (self.a, self.b)
def __str__(self):
return 'From str method of Test: a is %s, b is %s' % (self.a, self.b)"
gobject Functions
gobject Functions: "gobject.idle_add
def gobject.idle_add(callback, ...)
callback : a function to call when PyGTK is idle
... : optionals arguments to be passed to callback
Returns : an integer ID
The gobject.idle_add() function adds a function (specified by callback) to be called whenever there are no higher priority events pending to the default main loop. The function is given the default idle priority, gobject.PRIORITY_DEFAULT_IDLE. Additional arguments to pass to callback can be specified after callback. The idle priority can be specified as a keyword-value pair with the keyword 'priority'. If callback returns FALSE it is automatically removed from the list of event sources and will not be called again."
def gobject.idle_add(callback, ...)
callback : a function to call when PyGTK is idle
... : optionals arguments to be passed to callback
Returns : an integer ID
The gobject.idle_add() function adds a function (specified by callback) to be called whenever there are no higher priority events pending to the default main loop. The function is given the default idle priority, gobject.PRIORITY_DEFAULT_IDLE. Additional arguments to pass to callback can be specified after callback. The idle priority can be specified as a keyword-value pair with the keyword 'priority'. If callback returns FALSE it is automatically removed from the list of event sources and will not be called again."
Susam Pal: Compiler taking input while compiling
Susam Pal: Compiler taking input while compiling: "So, the code will have only one line: #include '/dev/stdin'. On Windows machine, CON represents the standard input, so: #include 'CON'"
Sunday, June 05, 2011
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