大约有 47,000 项符合查询结果（耗时：0.0513秒） [XML]
How to make execution pause, sleep, wait for X seconds in R?
...
See help(Sys.sleep).
For example, from ?Sys.sleep
testit <- function(x)
{
p1 <- proc.time()
Sys.sleep(x)
proc.time() - p1 # The cpu usage should be negligible
}
testit(3.7)
Yielding
> testit(3.7)
user system elapsed
0.000 0.0...
What is the at sign (@) in a batch file and what does it do?
... obvious for everyone but I didn't know that this only works when executed from a .batfile, i.e. it doesn't work straight from the command line.
– doABarrelRoll721
Feb 22 '16 at 15:11
...
Bash conditionals: how to “and” expressions? (if [ ! -z $VAR && -e $VAR ])
...
From the bash manpage:
[[ expression ]] - return a status of 0 or 1 depending on the evaluation of the conditional expression expression.
And, for expressions, one of the options is:
expression1 && expressi...
What is the correct way of using C++11's range-based for?
... ctor.
3 X copy ctor.
5 X copy ctor.
7 X copy ctor.
9
As it can be read from the output, copy constructor calls are made during range-based for loop iterations.
This is because we are capturing the elements from the container by value
(the auto x part in for (auto x : v)).
This is inefficient c...
Why should eval be avoided in Bash, and what should I use instead?
...g higher than &2) to your target:
exec 3<&0 # Redirect from stdin
exec 3>&1 # Redirect to stdout
exec 3>&2 # Redirect to stderr
exec 3> /dev/null # Don't save output anywhere
exec 3> file.txt # Redirect to file
exec 3> "$var" # Redirect ...
Update an outdated branch against master in a Git repo
...e master into your branch, and resolve the merge conflicts. Then, merging from your branch into master should be clean.
None of these is better than the other, they just have different trade-off patterns.
I would use the rebase approach, which gives cleaner overall results to later readers, in m...
How to change navbar collapse threshold using Twitter bootstrap-responsive?
...t your desired drop point of 550px. I modified the original query straight from the bootstrap-responsive css to reset all the styles applied to that specific query for the navbar elements and ported them to the new query that carries the drop point you need instead. This way we can commute all the s...
Is there a way to detect if an image is blurry?
...k of a way to tell if such a smooth area is "blurry", or to distinguish it from an out-of-focus area. You should ask this as a separate question (maybe on DSP.SE). Maybe someone else has better ideas.
– Niki
Nov 2 '12 at 8:28
...
What is a 'SAM type' in Java?
...ymous classes and are less restrictive on method naming. Take this example from the link:
class Person {
private final String name;
private final int age;
public static int compareByAge(Person a, Person b) { ... }
public static int compareByName(Person a, Person b) { ... }
}
Per...
SortedList, SortedDictionary and Dictionary
... for
SortedList(TKey, TValue).
If the list is populated all at once from sorted data,
SortedList(TKey, TValue) is faster than SortedDictionary(TKey,
TValue).
share
|
improve this answer
...