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“Failed to load platform plugin ”xcb“ ” while launching qt5 app on linux without qt installed
... place as your binary or shared library file. If that works, you may set LD_LIBRARY_PATH (hacky) or, as mentioned in the answer by @bossbarber, QT_QPA_PLATFORM_PLUGIN_PATH.
– csl
Oct 6 '16 at 7:06
...
Are tuples more efficient than lists in Python?
...2]
...
>>> import dis
>>> dis.dis(a)
2 0 LOAD_CONST 1 (1)
3 LOAD_CONST 2 (2)
6 LOAD_CONST 3 (3)
9 LOAD_CONST 4 (4)
12 LOAD_CONST 5 (5)
...
Always pass weak reference of self into block in ARC?
...olve by making an explicitly weak reference to self for the block to use:
__weak MyObject *weakSelf = self;
[self setMyBlock:^(id obj, NSUInteger idx, BOOL *stop) {
[weakSelf doSomethingWithObj:obj];
}];
But this should not be the default pattern you follow when dealing with blocks that ca...
Python Process Pool non-daemonic?
...
The multiprocessing.pool.Pool class creates the worker processes in its __init__ method, makes them daemonic and starts them, and it is not possible to re-set their daemon attribute to False before they are started (and afterwards it's not allowed anymore). But you can create your own sub-class o...
Regular expressions in an Objective-C Cocoa application
...ar expressions for substring searches, e.g. [myString rangeOfString:@"regex_here" options:NSRegularExpressionSearch]
– Nestor
Apr 28 '11 at 15:23
1
...
What is the Scala annotation to ensure a tail recursive function is optimized?
...e to Scala version 2.8.0.RC5 (Java HotSpot(TM) 64-Bit Server VM, Java 1.6.0_18).
Type in expressions to have them evaluated.
Type :help for more information.
scala> import scala.annotation.tailrec
import scala.annotation.tailrec
scala> class Tails {
| @tailrec def boom(x: Int): Int = {
...
Arduino Sketch upload issue - avrdude: stk500_recv(): programmer is not responding
... (with corresponding RX flashes on the board) right before the avrdude: ser_recv(): programmer is not responding error.
The trick is to hit the reset button on the board immediately before these three packets are sent. Then the program will be uploaded successfully.
...
Genymotion, “Unable to load VirtualBox engine.” on Mavericks. VBox is setup correctly
...s by installing VirtualBox 4.3.28 (https://www.virtualbox.org/wiki/Download_Old_Builds_4_3). The new 5.0.0 and 4.3.30 versions didn't work for me with Genymotion 2.5. None of the above solutions worked :(
It's also worth noting that at the time of writing, Genymotion's FAQ states the following:
...
Standardize data columns in R
...
z = runif(10, 10, 20))
dat
dat2 <- dat %>% mutate_at(c("y", "z"), ~(scale(.) %>% as.vector))
dat2
which gives me this:
> dat
x y z
1 29.75859 3.633225 14.56091
2 30.05549 3.605387 12.65187
3 30.21689 3.318092 13.04672
4 29.53086 3.079992...
Paging UICollectionView by cells, not screen
...nformance and set a value for pageWidth:
func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
let pageWidth = // The width your page should have (plus a possible margin)
let proportionalOffset = collectionView.contentOffset.x / pageWidth
indexOfCellBeforeDragging = Int(round(p...