大约有 32,000 项符合查询结果（耗时：0.0469秒） [XML]
How does python numpy.where() work?
...
How do they achieve internally that you are able to pass something like x > 5 into a method?
The short answer is that they don't.
Any sort of logical operation on a numpy array returns a boolean array. (i.e. __gt__, __lt__, etc all return boolea...
Initializing a struct to 0
...
The first is easiest(involves less typing), and it is guaranteed to work, all members will be set to 0[Ref 1].
The second is more readable.
The choice depends on user preference or the one which your coding standard mandates.
[Ref 1] Reference C99 Standard 6.7.8.21:
If there are fewe...
SQL query return data from multiple tables
...I-89 syntax (and if you are used to 89, may seem much less intuitive - but all I can say is to try it) as it is much easier to understand when the queries start getting more complex. Why use it? Is there a performance gain? The short answer is no, but it is easier to read once you get used to it. It...
Remove all but numbers from NSString
...thesis and hyphens as some phone numbers are formatted. How would I remove all characters except numbers from the string?
2...
CROSS JOIN vs INNER JOIN in SQL
...---------------------------------x
2. CROSS JOIN
Cross join selects the all the rows from the first table and all the rows from second table and shows as Cartesian product ie, with all possibilities
Consider we need to find all the teachers in the school and students irrespective of class teacher...
Git Pull While Ignoring Local Changes?
...it stash
git pull
git stash pop
I don't think it makes any sense to literally ignore the changes, though - half of pull is merge, and it needs to merge the committed versions of content with the versions it fetched.
share
...
PHP Get all subdirectories of a given directory
How can I get all sub-directories of a given directory without files, . (current directory) or .. (parent directory)
and then use each directory in a function?
...
Find XOR of all numbers in a given range
You are given a large range [a,b] where 'a' and 'b' can be typically between 1 and 4,000,000,000 inclusive. You have to find out the XOR of all the numbers in the given range.
...
Simple explanation of MapReduce?
...
Going all the way down to the basics for Map and Reduce.
Map is a function which "transforms" items in some kind of list to another kind of item and put them back in the same kind of list.
suppose I have a list of numbers: [1,2...
Peak detection in a 2D array
...ood = generate_binary_structure(2,2)
#apply the local maximum filter; all pixel of maximal value
#in their neighborhood are set to 1
local_max = maximum_filter(image, footprint=neighborhood)==image
#local_max is a mask that contains the peaks we are
#looking for, but also the ...