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How to calculate an angle from three points? [closed]
...P132 - P232) / (2 *
P12 * P13))
where P12 is the length of the segment from P1 to P2, calculated by
sqrt((P1x -
P2x)2 +
(P1y -
P2y)2)
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edited Aug 25 '16 at...
What is the difference between hg forget and hg remove?
I want mercurial to remove several files from the current state of the repository. However, I want the files to exist in prior history.
...
What's the difference between event.stopPropagation and event.preventDefault?
...
stopPropagation stops the event from bubbling up the event chain.
preventDefault prevents the default action the browser makes on that event.
Examples
preventDefault
$("#but").click(function (event) {
event.preventDefault()
})
$("#foo").click(f...
Move an array element from one array position to another
...
Here's a one liner I found on JSPerf....
Array.prototype.move = function(from, to) {
this.splice(to, 0, this.splice(from, 1)[0]);
};
which is awesome to read, but if you want performance (in small data sets) try...
Array.prototype.move2 = function(pos1, pos2) {
// local variables
v...
How to extract an assembly from the GAC?
...
I used the advice from this article to get an assembly from the GAC.
Get DLL Out of The GAC
DLLs once
deployed in GAC (normally located at
c:\windows\assembly) can’t be viewed
or used as a normal DLL file. They
can’t be ...
Detect & Record Audio in Python
...o Nick Fortescue's answer, here's a more complete example of how to record from the microphone and process the resulting data:
from sys import byteorder
from array import array
from struct import pack
import pyaudio
import wave
THRESHOLD = 500
CHUNK_SIZE = 1024
FORMAT = pyaudio.paInt16
RATE = 441...
Circular (or cyclic) imports in Python
...ty straightforward really. Just remember the following:
'import' and 'from xxx import yyy' are executable statements. They execute
when the running program reaches that line.
If a module is not in sys.modules, then an import creates the new module
entry in sys.modules and then executes...
Sending HTML email using Python
...
From Python v2.7.14 documentation - 18.1.11. email: Examples:
Here’s an example of how to create an HTML message with an alternative plain text version:
#! /usr/bin/python
import smtplib
from email.mime.multipart im...
Where do I find the current C or C++ standard documents?
...d C++ standards documents in PDF are:
C++17 – ISO/IEC 14882:2017: $116 from ansi.org
C++14 – ISO/IEC 14882:2014: $90 NZD (about $60 US) from Standards New Zealand
C++11 – ISO/IEC 14882:2011: $60 from ansi.org $60 from Techstreet
C++03 – ISO 14882:2003: $30 from ansi.org $48 from SAI Global...
How does Access-Control-Allow-Origin header work?
...Cross-Origin Resource Sharing) header.
When Site A tries to fetch content from Site B, Site B can send an Access-Control-Allow-Origin response header to tell the browser that the content of this page is accessible to certain origins. (An origin is a domain, plus a scheme and port number.) By defa...