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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 can I scan barcodes on iOS?
...tWithDevice:self.device error:nil];
self.session = [[AVCaptureSession alloc] init];
self.output = [[AVCaptureMetadataOutput alloc] init];
[self.session addOutput:self.output];
[self.session addInput:self.input];
[self.output setMetadataObjectsDelegate:self queue:dispatch_get_m...
Increase heap size in Java
...
It is possible to increase heap size allocated by the JVM by using command line options
Here we have 3 options
-Xms<size> set initial Java heap size
-Xmx<size> set maximum Java heap size
-Xss<size> set java thread stack si...
Find out how much memory is being used by an object in Python [duplicate]
... different implementation for small number of keys and sometimes they over allocate entries).
There is a big chunk of code (and an updated big chunk of code) out there to try to best approximate the size of a python object in memory.
You may also want to check some old description about PyObject ...
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
...
C# int to byte[]
...sides, doing the assignment is cheap since it does not copy the memory nor allocate new memory, it just adds a new name to the already allocated array. So why not do it?
– paracycle
May 7 '19 at 15:54
...
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.
...
How to resize superview to fit all subviews with autolayout?
...ad];
// INIT ALL REQUIRED UI ELEMENTS
self.contentView = [[UIView alloc] init];
self.myLabel = [[UILabel alloc] init];
self.myOtherLabel = [[UILabel alloc] init];
NSDictionary *viewsDictionary = NSDictionaryOfVariableBindings(_contentView, _myLabel, _myOtherLabel);
// TURN ...
Python (and Python C API): __new__ versus __init__
...One example is when you unpickle objects from a pickle file, they will get allocated (__new__) but not initialised (__init__).
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