Tutorial by Examples: p

if a directory contain 2 files: $ ls makefile example.txt and makefile contain the following text %.gz: % gzip $< then you can obtain example.txt.gz by typing in the shell $ make -f makefile example.txt.gz the makefile consist of only one rule that instruct make how to create a...

The following utility can be used for auto-completion of commands: $ which aws_completer /usr/bin/aws_completer $ complete -C '/usr/bin/aws_completer' aws For future shell sessions, consider add this to your ~/.bashrc $ echo "complete -C '/usr/bin/aws_completer' aws" >> ~/.b...

Consider you want to predict the correct answer for XOR popular problem. You Knew what is XOR(e.g [x0 x1] => y). for example [0 0] => 0, [0 1] => [1] and... #Load Sickit learn data from sklearn.neighbors import KNeighborsClassifier #X is feature vectors, and y is correct label(To train...

DECLARE v_counter NUMBER(2); BEGIN v_counter := 0; LOOP v_counter := v_counter + 1; dbms_output.put_line('Line number' || v_counter); EXIT WHEN v_counter = 10; END LOOP; END;

It is very easy to build a simple C++ project. Here is an example of a SConstruct file that does so: env=Environment() env.Program('hello', Glob('src/*.cpp')) This creates the executable hello composed of all the sources in src with extension cpp.

This example shows more detailed build settings: env=Environment( CPPPATH='/usr/include/boost/', CPPDEFINES=['foo'], LIBS=['bar'], SCONS_CXX_STANDARD='c++11') env.Program('hello', Glob('src/*.cpp')) This builds the executable hello from all the cpp files in src, with the f...

It is a dialog which prompts user to select date using DatePicker. The dialog requires context, initial year, month and day to show the dialog with starting date. When the user selects the date it callbacks via DatePickerDialog.OnDateSetListener. public void showDatePicker(Context context,int init...

This kind of schema will be useful if you want to keep trace of your items by insertion time or update time. var mongoose = require('mongoose'); var Schema = mongoose.Schema; // Creates a User Schema. var user = new Schema({ name: { type: String }, ...

In this example, we rewrite url's of the form http://example.com/topic/id-seoname to a php script that takes an id as input. This example expects the rule to be in "per-directory" context. RewriteEngine on RewriteRule ^topic/([0-9]+)-[^/]*/?$ /topics.php?id=$1 [L] In this example, t...

To match a query string, a condition must be added to the RewriteRule. This is done by putting RewriteCond directives before the corresponding rule. In the following example we dynamically internally rewrite an old url to a new url. RewriteCond %{QUERY_STRING} ^name=([^&]*)$ RewriteRule ^oldsc...

The Cholesky decomposition is a method to decompose an hermitean, positiv definite matrix into an upper triangular matrix and its transpose. It can be used to solve linear equations systems and and is around twice as fast as LU-decomposition. A = [4 12 -16 12 37 -43 -16 -43 98]; R = chol...

This method will decompose a matrix into an upper triangular and an orthogonal matrix. A = [4 12 -16 12 37 -43 -16 -43 98]; R = qr(A); This will return the upper triangular matrix while the following will return both matrices. [Q,R] = qr(A); The following plot will display the run...

Hereby a matrix will be decomposed into an upper trangular and an lower triangular matrix. Often it will be used to increase the performance and stability (if it's done with permutation) of Gauß elimination. However, quite often does this method not or badly work as it is not stable. For example A...

OpenCv image read from file system in Java import org.opencv.core.Core; import org.opencv.core.Mat; import org.opencv.imgcodecs.Imgcodecs; public class Giris { public static void main(String[] args) { //Load native library System.loadLibrary(Core.NATIVE_LIBRARY_NAME...

This is an example how to get the play an audio file which you already have on your pc/laptop .First create a new directory under res and name it as raw like this copy the audio which you want to play into this folder .It may be a .mp3 or .wav file. Now for example on button click you want to pl...

Numpy provides a cross function for computing vector cross products. The cross product of vectors [1, 0, 0] and [0, 1, 0] is [0, 0, 1]. Numpy tells us: >>> a = np.array([1, 0, 0]) >>> b = np.array([0, 1, 0]) >>> np.cross(a, b) array([0, 0, 1]) as expected. While cr...

Either input can be an array of 3- (or 2-) element vectors. >>> a=np.array([[1,0,0],[0,1,0],[0,0,1]]) >>> b=np.array([1,0,0]) >>> np.cross(a,b) array([[ 0, 0, 0], [ 0, 0, -1], [ 0, 1, 0]]) The result in this case is array([np.cross(a[0],b), np.c...

Step 1: Add the dependency of latest ACRA AAR to your application gradle(build.gradle). Step 2: In your application class(the class which extends Application; if not create it) Add a @ReportsCrashes annotation and override the attachBaseContext() method. Step 3: Initialize the ACRA class in your...

Animation to show how selection sort works The below example shows selection sort in Python def sort_selection(my_list): for pos_upper in xrange( len(my_list)-1, 0, -1): max_pos = 0 for i in xrange(1, pos_upper + 1): if(my_list[i] > my_list[max_pos]): max_po...

We may forget to apply the Antiforgery attribute for each POST request so we should make it by default. This sample will make sure Antiforgery filter will always be applied to every POST request. Firstly create new AntiForgeryTokenFilter filter: //This will add ValidateAntiForgeryToken Attribute t...