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Remove columns from dataframe where ALL values are NA
...m.time({df1 <- bd[,colSums(is.na(bd) < nrow(bd))]})
# error -- can't allocate vector of size ...
system.time({df2 <- bd[, !apply(is.na(bd), 2, all)]})
# error -- can't allocate vector of size ...
system.time({df3 <- Filter(function(x)!all(is.na(x)), bd)})
## user system elapsed
## 0.26...
How to draw a custom UIView that is just a circle - iPhone app
... could use QuartzCore and do something this --
self.circleView = [[UIView alloc] initWithFrame:CGRectMake(10,20,100,100)];
self.circleView.alpha = 0.5;
self.circleView.layer.cornerRadius = 50; // half the width/height
self.circleView.backgroundColor = [UIColor blueColor];
...
How to create a multiline UITextfield?
... UITextField.
CGFloat tapLlblHeight = 10;
UILabel *tapEditLbl = [[UILabel alloc] initWithFrame:CGRectMake(20, textField.frame.size.height - tapLlblHeight - 2, 70, tapLlblHeight)];
tapEditLbl.backgroundColor = [UIColor clearColor];
tapEditLbl.textColor = [UIColor whiteColor];
tapEditLbl.text = @"Tap...
How to store values from foreach loop into an array?
... Declaring $items = array(); before foreach is not even necessary, right? php will just create an empty array
– BassMHL
Oct 2 '17 at 2:25
...
Should MySQL have its timezone set to UTC?
...negative values from FROM_UNIXTIME
Sources:
https://bugs.mysql.com/bug.php?id=68861
http://dev.mysql.com/doc/refman/5.0/en/date-and-time-functions.html
http://dev.mysql.com/doc/refman/5.1/en/datetime.html
http://en.wikipedia.org/wiki/Coordinated_Universal_Time
http://shafiqissani.wordpress.com/2...
PHPUnit assert that an exception was thrown?
...
<?php
require_once 'PHPUnit/Framework.php';
class ExceptionTest extends PHPUnit_Framework_TestCase
{
public function testException()
{
$this->expectException(InvalidArgumentException::class);
// or f...
Appending a vector to a vector [duplicate]
... = orig;
std::copy(v.begin(), v.end(), std::back_inserter(v));
// std::bad_alloc exception is generated
// GOOD, but I can't guarantee it will work with any STL:
v = orig;
v.reserve(v.size()*2);
v.insert(v.end(), v.begin(), v.end());
// Now v contains: { "first", "second", "first", "second" }
// G...
Making an array of integers in iOS
...nd of expert-level optimization is under the hood of NSArray? Smart memory allocation that simply probably doubles the size of allocated memory once it hits the limit? :)p
– Ben Sinclair
May 18 '14 at 0:37
...
Measuring the distance between two coordinates in PHP
...- http://www.codexworld.com/distance-between-two-addresses-google-maps-api-php/
$latitudeFrom = '22.574864';
$longitudeFrom = '88.437915';
$latitudeTo = '22.568662';
$longitudeTo = '88.431918';
//Calculate distance from latitude and longitude
$theta = $longitudeFrom - $longitudeTo;
$dist = sin(de...
Variable declaration in a C# switch statement [duplicate]
...e case, however, to create a smaller scope. As for whether they're created/allocated - the stack frame has enough space for all the local variables in a method (leaving aside the complexities of captured variables). It's not like that space is allocated during the method's execution.
...