Tutorial by Examples: d

Reverse-direction for loop

A for loop iterates from the starting value down to the ending value inclusive, as a "count-down" example. program CountDown; {$APPTYPE CONSOLE} var i : Integer; begin for i := 10 downto 0 do WriteLn(i); end. Output: 10 9 8 7 6 5 4 3 2 1 0

Embarcadero Delphi • For Loops

Declaration of ABAP Internal Tables

Internal Table Declaration Based on Local Type Definition " Declaration of type TYPES: BEGIN OF ty_flightb, id TYPE fl_id, dat TYPE fl_date, seatno TYPE fl_seatno, firstname TYPE fl_fname, lastname TYPE fl_lname, fl...

ABAP • Internal Tables

Read, Write and Insert into Internal Tables

Read, write and insert into internal tables with a header line: " Read from table with header (using a loop): LOOP AT i_compc_all. " Loop over table i_compc_all and assign header line CASE i_compc_all-ftype. " Read cell ftype from header line from table i_com...

ABAP • Internal Tables

Avoiding Divide by Zero with NumberSet Operations

In order to avoid a divide by zero with a numberSet (what you get after a reduction like avg()) you can short-circuit the logic: $five = min(q("sum:rate{counter,,1}:haproxy.frontend.hrsp{}{status_code=5xx}", "1h", "")) $two = avg(q("sum:rate{counter,,1}:haproxy.f...

Bosun • Expression Tips and Tricks

Avoiding Divide by Zero in SeriesSet Operations

With series operations, things are dropped from the left side if there is no corresponding timestamp/datapoint in the right side. You can mix this with the dropbool function to avoid divide by zero: $five = q("sum:rate{counter,,1}:haproxy.frontend.hrsp{}{status_code=5xx}", "1h",...

Bosun • Expression Tips and Tricks

Capture canvas and Save as webM video

Creating a WebM video from canvas frames and playing in canvas, or upload, or downloading. Example capture and play canvas name = "CanvasCapture"; // Placed into the Mux and Write Application Name fields of the WebM header quality = 0.7; // good quality 1 Best < 0.7 ok to poor fps =...

html5-canvas • Media types and the canvas

Simple ServiceLoader Example

The ServiceLoader is a simple and easy to use built-in mechanism for dynamic loading of interface implementations. With the service loader - providing means for instantation (but not the wiring) - a simple dependency injection mechanism can be built in Java SE. With the ServiceLoader interface and ...

Java Language • ServiceLoader

Alternate installation (not conda)

Alternate ways to install SymPy from conda. conda is the recommended way, but these are some alternate ways. Including: git, pip, etc.

sympy • Getting started with sympy

Pie Chart with Demo

<!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(function(){ var canvas = document.getElementById("canvas"); var ctx = canvas.getContext(&...

html5-canvas • Charts & Diagrams

A function that accepts named parameters

foo() { while [[ "$#" -gt 0 ]] do case $1 in -f|--follow) local FOLLOW="following" ;; -t|--tail) local TAIL="tail=$2" ;; esac shift done echo "FOLLOW: $FOLLOW" echo "TAIL: $...

Bash • Functions

Rotate an Image or Path around it's centerpoint

Steps#1-5 below allow any image or path-shape to be both moved anywhere on the canvas and rotated to any angle without changing any of the image/path-shape's original point coordinates. Move the canvas [0,0] origin to the shape's center point context.translate( shapeCenterX, shapeCenterY ); ...

html5-canvas • Transformations

Mouse coordinates after resizing (or scrolling)

Canvas apps often rely heavily on user interaction with the mouse, but when the window is resized, the mouse event coordinates that canvas relies on are likely changed because resizing causes the canvas to be offset in a different position relative to the window. Thus, responsive design requires tha...

html5-canvas • Responsive Design

Finding information about a running process

ps aux | grep <search-term> shows processes matching search-term Example: root@server7:~# ps aux | grep nginx root 315 0.0 0.3 144392 1020 ? Ss May28 0:00 nginx: master process /usr/sbin/nginx www-data 5647 0.0 1.1 145124 3048 ? S Jul18 2:53 nginx: worke...

Bash • Jobs and Processes

basic channel operations: creating, putting, taking, closing, and buffers.

core.async is about making processes that take values from and put values into channels. (require [clojure.core.async :as a]) Creating channels with chan You create a channel using the chan function: (def chan-0 (a/chan)) ;; unbuffered channel: acts as a rendez-vous point. (def chan-1 (a/chan...

clojure • core.async

Introduction to Symmetric and Asymmetric Encryption

You can improve the security for data transit or storing by implementing encrypting techniques. Basically there are two approaches when using System.Security.Cryptography: symmetric and asymmetric. Symmetric Encryption This method uses a private key in order to perform the data transformation. ...

C# Language • Cryptography (System.Security.Cryptography)

Create a simple document

This very simple snippet of XQuery can be executed in QueryConsole using the built-in "Documents" database as a sandbox. Each piece of the snippet has a comment to explain what the following line of code means. xquery version "1.0-ml"; (: Let's first insert a simple document to...