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What does .SD stand for in data.table in R
... may help you see what .SD is:
DT[ , .SD[ , paste(x, v, sep="", collapse="_")], by=y]
# y V1
# 1: 1 a1_b3_c5
# 2: 3 a2_b4_c6
Basically, the by=y statement breaks the original data.table into these two sub-data.tables
DT[ , print(.SD), by=y]
# <1st sub-data.table, called '.SD' while i...
Symbolicating iPhone App Crash Reports
...above (using cd command)
Run atos -arch armv7 -o APPNAME.app/APPNAME MEMORY_LOCATION_OF_CRASH. The memory location should be the one at which the app crashed as per the report.
Ex: atos -arch armv7 -o 'APPNAME.app'/'APPNAME' 0x0003b508
This would show you the exact line, method name which resul...
How to test that no exception is thrown?
...write, will work.
Such a method call can look like this: existingUserById_ShouldReturn_UserObject. If this method fails (e.g.: an exception is thrown) then you know something went wrong and you can start digging.
By adding another test (nonExistingUserById_ShouldThrow_IllegalArgumentException) th...
Connect Java to a MySQL database
... as well.
CREATE DATABASE javabase DEFAULT CHARACTER SET utf8 COLLATE utf8_unicode_ci;
Create an user for Java and grant it access. Simply because using root is a bad practice.
CREATE USER 'java'@'localhost' IDENTIFIED BY 'password';
GRANT ALL ON javabase.* TO 'java'@'localhost' IDENTIFIED BY 'pa...
Parse usable Street Address, City, State, Zip from a string [closed]
...nteger = 0 To streetMarkerIndex
If IsNumeric(splitString(counter)) _
Or splitString(counter).ToString.ToLower = "po" _
Or splitString(counter).ToString().ToLower().Replace(".", "") = "po" Then
addressIndex = counter
Exit For
End If
...
Adding an arbitrary line to a matplotlib plot in ipython notebook
...e taken in account in the legend by adding a label argument starting with "_". Ex: plt.plot([70, 70], [100, 250], 'k-', lw=2, label="_not in legend")
– gcalmettes
Oct 29 '16 at 5:40
...
Shall we always use [unowned self] inside closure in Swift
...rmance sensitive weak vars to unowned now.
– original_username
Jul 14 '16 at 9:45
"The closure lifetime is independent...
Does Java SE 8 have Pairs or Tuples?
...
public static void main(String[] args) {
boolean [][] directed_acyclic_graph = new boolean[][]{
{false, true, false, true, false, true},
{false, false, false, true, false, true},
{false, false, false, true, false, true},
...
How do I send a cross-domain POST request via JavaScript?
...r a smaller code snippet.
In postHere.php setup the following:
switch ($_SERVER['HTTP_ORIGIN']) {
case 'http://from.com': case 'https://from.com':
header('Access-Control-Allow-Origin: '.$_SERVER['HTTP_ORIGIN']);
header('Access-Control-Allow-Methods: GET, PUT, POST, DELETE, OPTIONS');
...
How to get device make and model on iOS?
...should be:
// Output on a simulator
@"i386" on 32-bit Simulator
@"x86_64" on 64-bit Simulator
// Output on an iPhone
@"iPhone1,1" on iPhone
@"iPhone1,2" on iPhone 3G
@"iPhone2,1" on iPhone 3GS
@"iPhone3,1" on iPhone 4 (GSM)
@"iPhone3,2" on iPhone 4 (GSM Rev A)
@"iPhone3,3" on iPhone 4 (CDM...