大约有 46,000 项符合查询结果（耗时：0.0624秒） [XML]
How to randomize (or permute) a dataframe rowwise and columnwise?
...,]
> df2
a b c
3 0 1 0
4 0 0 0
2 1 0 0
1 1 1 0
By default sample() randomly reorders the elements passed as the first argument. This means that the default size is the size of the passed array. Passing parameter replace=FALSE (the default) to sample(...) ensures that sampling is done withou...
Difference between break and continue statement
Can anyone tell me the difference between break and continue statements?
21 Answers
...
Programmatically Lighten or Darken a hex color (or rgb, and blend colors)
...ecific amount. Just pass in a string like "3F6D2A" for the color ( col ) and a base10 integer ( amt ) for the amount to lighten or darken. To darken, pass in a negative number (i.e. -20 ).
...
How do SO_REUSEADDR and SO_REUSEPORT differ?
The man pages and programmer documentations for the socket options SO_REUSEADDR and SO_REUSEPORT are different for different operating systems and often highly confusing. Some operating systems don't even have the option SO_REUSEPORT . The WEB is full of contradicting information regarding th...
How to make good reproducible pandas examples
Having spent a decent amount of time watching both the r and pandas tags on SO, the impression that I get is that pandas questions are less likely to contain reproducible data. This is something that the R community has been pretty good about encouraging, and thanks to guides like this , newc...
Can I set background image and opacity in the same property?
I can see in CSS references how to set image transparency and how to set a background image . But how can I combine these two in order to set a transparent background image?
...
Formula to determine brightness of RGB color
...GB values. I know it can't be as simple as adding the RGB values together and having higher sums be brighter, but I'm kind of at a loss as to where to start.
...
What to use as an initial version? [closed]
...ersion 1.0.0. As soon as I have some stuff together, I release it as 1.0.0 and move on with 1.1.0.
12 Answers
...
Does ruby have real multithreading?
...e confusing two very different things here: the
Ruby Programming Language and the specific threading model of one
specific implementation of the Ruby Programming Language. There
are currently around 11 different implementations of the Ruby
Programming Language, with very different and unique thr...
Find MongoDB records where array field is not empty
... To me that's the correct approach, since it makes sure the array exists and is not empty.
– LeandroCR
Mar 19 '15 at 14:34
...