大约有 47,000 项符合查询结果（耗时：0.0563秒） [XML]
Getting pids from ps -ef |grep keyword
...
234
You can use pgrep as long as you include the -f options. That makes pgrep match keywords in th...
How to use the 'sweep' function
...ation defined by FUN.
For instance, if you want to add 1 to the 1st row, 2 to the 2nd, etc. of the matrix you defined, you will do:
sweep (M, 1, c(1: 4), "+")
I frankly did not understand the definition in the R documentation either, I just learned by looking up examples.
...
How to assert two list contain the same elements in Python? [duplicate]
...
As of Python 3.2 unittest.TestCase.assertItemsEqual(doc) has been replaced by unittest.TestCase.assertCountEqual(doc) which does exactly what you are looking for, as you can read from the python standard library documentation. The method is...
rotating axis labels in R
...able(Ni <- stats::rpois(100, lambda=5))
r <- barplot(tN, col=rainbow(20), las=1)
That represents the style of axis labels. (0=parallel, 1=all horizontal, 2=all perpendicular to axis, 3=all vertical)
share
...
Transparent ARGB hex value
...
205
Transparency is controlled by the alpha channel (AA in #AARRGGBB). Maximal value (255 dec, FF ...
Applying a function to every row of a table using dplyr?
...
202
As of dplyr 0.2 (I think) rowwise() is implemented, so the answer to this problem becomes:
ir...
cannot load such file — zlib even after using rvm pkg install zlib
...
201
I ended up installing zlib from apt-get and then reinstalling ruby to not use the rvm director...
How do write IF ELSE statement in a MySQL query
...ably want to use a CASE expression.
They look like this:
SELECT col1, col2, (case when (action = 2 and state = 0)
THEN
1
ELSE
0
END)
as state from tbl1;
share
|
improve this an...
How add “or” in switch statements?
...
326
By stacking each switch case, you achieve the OR condition.
switch(myvar)
{
case 2:
ca...
What does 'synchronized' mean?
...hout the synchronized keyword, your thread 1 may not see the change thread 2 made to foo, or worse, it may only be half changed. This would not be what you logically expect.
Again, this is a non-trivial topic in Java. To learn more, explore topics here on SO and the Interwebs about:
Concurrenc...