大约有 47,000 项符合查询结果（耗时：0.0657秒） [XML]
Why is the shovel operator (
I am working through Ruby Koans.
7 Answers
7
...
Replacing NAs with latest non-NA value
In a data.frame (or data.table), I would like to "fill forward" NAs with the closest previous non-NA value. A simple example, using vectors (instead of a data.frame ) is the following:
...
In javascript, is an empty string always false as a boolean?
in javascript,
5 Answers
5
...
range() for floats
Is there a range() equivalent for floats in Python?
21 Answers
21
...
What is the significance of initializing direction arrays below with given values when developing ch
I am new to competitive programming, and I noticed frequently, many of the great coders have these four lines in their code (particularly in those involving arrays):
...
Gradients on UIView and UILabels On iPhone [duplicate]
My application needs to display text in either a UIView or UILabel but the back ground must be a gradient as opposed to a true UIColor . Using a graphics program to create desired look is no good as the text may vary depending on data returned from a server.
...
Fastest way to list all primes below N
This is the best algorithm I could come up.
35 Answers
35
...
Changing UIImage color
I'm trying to change color of UIImage. My code:
13 Answers
13
...
Simple Digit Recognition OCR in OpenCV-Python
I am trying to implement a "Digit Recognition OCR" in OpenCV-Python (cv2). It is just for learning purposes. I would like to learn both KNearest and SVM features in OpenCV.
...
postgresql return 0 if returned value is null
I have a query that returns avg(price)
3 Answers
3
...