大约有 48,000 项符合查询结果（耗时：0.0417秒） [XML]
Summarizing multiple columns with dplyr? [duplicate]
... a bit with the dplyr-syntax. I have a data frame with different variables and one grouping variable. Now I want to calculate the mean for each column within each group, using dplyr in R.
...
REST API Token-based Authentication
...
Let me seperate up everything and solve approach each problem in isolation:
Authentication
For authentication, baseauth has the advantage that it is a mature solution on the protocol level. This means a lot of "might crop up later" problems are already ...
OSGi: What are the differences between Apache Felix and Apache Karaf?
...her features such as a console, an SSH remoting mechanism, a file deployer and more.
In this diagram of the Karaf architecture, Felix (or other OSGi implementation - currently Equinox is also supported) is the OSGi box, the other boxes are the features added by Karaf:
Therefore, unless you have ...
What is the difference between fastcgi and fpm?
...d somewhere that fpm means FastCGI process manager. Does that mean fastcgi and fpm are same? If they are same, then why do we have two different macports variants for php namely
"php5 +fastcgi" and
"php5 +fpm"
...
Search and replace a line in a file in Python
I want to loop over the contents of a text file and do a search and replace on some lines and write the result back to the file. I could first load the whole file in memory and then write it back, but that probably is not the best way to do it.
...
Programmatically create a UIView with color gradient
...gColor]
view.layer.insertSublayer(gradient, at: 0)
Info: use startPoint and endPoint to change direction of gradient.
If there are any other views added onto this UIView (such as a UILabel), you may want to consider setting the background color of those UIView’s to [UIColor clearColor] so the ...
Why are preprocessor macros evil and what are the alternatives?
...d encountered a phrase like "macro should never be used", "macro are evil" and so on, my question is: why? With the new C++11 is there a real alternative after so many years?
...
Angularjs: 'controller as syntax' and $watch
...ght context. However, I found his answer cleaner.
Having that said, first and foremost, you have to understand the underlying idea behind it.
UPDATE 2:
For those who use ES6, by using arrow function you get a function with the right context OOTB.
$scope.$watch(() => this.name, function (newVa...
What is the correct syntax for 'else if'?
... python "else if" is spelled "elif".
Also, you need a colon after the elif and the else.
Simple answer to a simple question. I had the same problem, when I first started (in the last couple of weeks).
So your code should read:
def function(a):
if a == '1':
print('1a')
elif a == '2...
How does this print “hello world”?
...th this codification scheme you can have all 26 (one case) english letters and 6 symbols (being space among them).
Algorithm description
The >>= 5 in the for-loop jumps from group to group, then the 5-bits group gets isolated ANDing the number with the mask 31₁₀ = 11111₂ in the sentenc...