大约有 47,000 项符合查询结果（耗时：0.0499秒） [XML]
How do I make a list of data frames?
How do I make a list of data frames and how do I access each of those data frames from the list?
8 Answers
...
In Ruby, is there an Array method that combines 'select' and 'map'?
...
I usually use map and compact together along with my selection criteria as a postfix if. compact gets rid of the nils.
jruby-1.5.0 > [1,1,1,2,3,4].map{|n| n*3 if n==1}
=> [3, 3, 3, nil, nil, nil]
jruby-1.5.0 > [1,1,1,2,3,4].m...
Generate a random point within a circle (uniformly)
I need to generate a uniformly random point within a circle of radius R .
21 Answers
...
Why do enum permissions often have 0, 1, 2, 4 values?
Why are people always using enum values like 0, 1, 2, 4, 8 and not 0, 1, 2, 3, 4 ?
7 Answers
...
Drop all the tables, stored procedures, triggers, constraints and all the dependencies in one sql st
...which I can clean a database in SQl Server 2005 by dropping all the tables and deleting stored procedures, triggers, constraints and all the dependencies in one SQL statement?
...
What is the difference between & and && in Java?
...& operator in Java is used for verifying whether both its boolean operands are true , and the & operator is used to do Bit-wise operations on two integer types.
...
What would cause an algorithm to have O(log n) complexity?
My knowledge of big-O is limited, and when log terms show up in the equation it throws me off even more.
6 Answers
...
Difference between map, applymap and apply methods in Pandas
...rame’s apply method does exactly this:
In [116]: frame = DataFrame(np.random.randn(4, 3), columns=list('bde'), index=['Utah', 'Ohio', 'Texas', 'Oregon'])
In [117]: frame
Out[117]:
b d e
Utah -0.029638 1.081563 1.280300
Ohio 0.647747 0.831136 -1.549481
Tex...
Where can I find the TypeScript version installed in Visual Studio?
Maybe it's obvious, but I checked everywhere (besides the right place) and googled it. Nothing.
14 Answers
...
Why does 2 mod 4 = 2?
...ion. My term does not start for two more weeks so I can't ask a professor, and the suspense would kill me.
19 Answers
...