大约有 48,000 项符合查询结果（耗时：0.0647秒） [XML]
Changing column names of a data frame
...d=1:3, worse=rnorm(3))
R> X
bad worse
1 1 -2.440467
2 2 1.320113
3 3 -0.306639
R> colnames(X) <- c("good", "better")
R> X
good better
1 1 -2.440467
2 2 1.320113
3 3 -0.306639
You can also subset:
R> colnames(X)[2] <- "superduper"
...
Global variables in Java
...
answered Jan 10 '11 at 12:04
AbiAbi
4,19433 gold badges1818 silver badges2727 bronze badges
...
How do I create a basic UIButton programmatically?
...
1191
Here's one:
UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
[button addTarg...
What's the most appropriate HTTP status code for an “item not found” error page
...
answered Apr 9 '11 at 11:47
bmarguliesbmargulies
88.7k3232 gold badges162162 silver badges282282 bronze badges
...
Reshaping data.frame from wide to long format
...nia 1952 10,058
7: AFG Afghanistan 1953 23,557
8: ALB Albania 1953 11,123
9: AFG Afghanistan 1954 24,555
10: ALB Albania 1954 12,246
Some alternative notations:
melt(setDT(wide), id.vars = 1:2, variable.name = "year")
melt(setDT(wide), measure.vars = 3:7, variable.name = "year")
m...
The tilde operator in C
...e ~ operator is bitwise NOT, it inverts the bits in a binary number:
NOT 011100
= 100011
share
|
improve this answer
|
follow
|
...
Is there a Mutex in Java?
...
112
See this page: http://www.oracle.com/technetwork/articles/javase/index-140767.html
It has a ...
How to make a HTTP request using Ruby on Rails?
...|
edited Jun 22 '14 at 12:11
Martin Tournoij
22.1k1717 gold badges8585 silver badges116116 bronze badges
...
Why is the minimalist, example Haskell quicksort not a “true” quicksort?
...
11 Answers
11
Active
...
How to hide only the Close (x) button?
...
Alex Essilfie
11.3k99 gold badges6464 silver badges102102 bronze badges
answered Sep 4 '11 at 20:10
Daniel A. White...