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Dynamically select data frame columns using $ and a character value
...itten as
`$`(df , V1)
or indeed
`$`(df , "V1")
But...
`$`(df , paste0("V1") )
...for instance will never work, nor will anything else that must first be evaluated in the second argument. You may only pass a string which is never evaluated.
Instead use [ (or [[ if you want to extract only...
Animation CSS3: display + opacity
...:hover .child
{
display: block;
-webkit-animation: fadeInFromNone 0.5s ease-out;
-moz-animation: fadeInFromNone 0.5s ease-out;
-o-animation: fadeInFromNone 0.5s ease-out;
animation: fadeInFromNone 0.5s ease-out;
}
@-webkit-keyframes fadeInFromNone {
0% {
display: no...
Small Haskell program compiled with GHC into huge binary
... for GNU/Linux 2.6.27, not stripped
$ ldd A
linux-vdso.so.1 => (0x00007fff1b9ff000)
libXrandr.so.2 => /usr/lib/libXrandr.so.2 (0x00007fb21f418000)
libX11.so.6 => /usr/lib/libX11.so.6 (0x00007fb21f0d9000)
libGLU.so.1 => /usr/lib/libGLU.so.1 (0x00007fb21ee6d000)
lib...
Find XOR of all numbers in a given range
...ven a large range [a,b] where 'a' and 'b' can be typically between 1 and 4,000,000,000 inclusive. You have to find out the XOR of all the numbers in the given range.
...
Sample random rows in dataframe
...
460
First make some data:
> df = data.frame(matrix(rnorm(20), nrow=10))
> df
X1 ...
How to host a Node.Js application in shared hosting [closed]
...
160
You can run node.js server on a typical shared hosting with Linux, Apache and PHP (LAMP). I hav...
How do I get bit-by-bit data from an integer value in C?
...wanted){
int *bits = malloc(sizeof(int) * bitswanted);
int k;
for(k=0; k<bitswanted; k++){
int mask = 1 << k;
int masked_n = n & mask;
int thebit = masked_n >> k;
bits[k] = thebit;
}
return bits;
}
int main(){
int n=7;
int bitswanted = 5;
int...
Use ffmpeg to add text subtitles [closed]
...
202
ffmpeg -i infile.mp4 -i infile.srt -c copy -c:s mov_text outfile.mp4
-vf subtitles=infile.srt...
Why is it slower to iterate over a small string than a small list?
...
TL;DR
The actual speed difference is closer to 70% (or more) once a lot of the overhead is removed, for Python 2.
Object creation is not at fault. Neither method creates a new object, as one-character strings are cached.
The difference is unobvious, but is likely created f...
Using async/await for multiple tasks
... |
edited Jul 7 '16 at 10:41
answered Sep 9 '12 at 11:35
...