大约有 43,000 项符合查询结果（耗时：0.0379秒） [XML]
How to access the ith column of a NumPy multidimensional array?
...
>>> test[:,0]
array([1, 3, 5])
Similarly,
>>> test[1,:]
array([3, 4])
lets you access rows. This is covered in Section 1.4 (Indexing) of the NumPy reference. This is quick, at least in my experience. It's certainly much quicker ...
For each row return the column name of the largest value
...
100
One option using your data (for future reference, use set.seed() to make examples using sample...
What is the “N+1 selects problem” in ORM (Object-Relational Mapping)?
The "N+1 selects problem" is generally stated as a problem in Object-Relational mapping (ORM) discussions, and I understand that it has something to do with having to make a lot of database queries for something that seems simple in the object world.
...
Format a number as 2.5K if a thousand or more, otherwise 900
I need to show a currency value in the format of 1K of equal to one thousand, or 1.1K, 1.2K, 1.9K etc, if its not an even thousands, otherwise if under a thousand, display normal 500, 100, 250 etc, using javascript to format the number?
...
Moving decimal places over in a double
So I have a double set to equal 1234, I want to move a decimal place over to make it 12.34
9 Answers
...
How can I apply a function to every row/column of a matrix in MATLAB?
...an apply a function to every item in a vector by saying, for example, v + 1 , or you can use the function arrayfun . How can I do it for every row/column of a matrix without using a for loop?
...
Emulate ggplot2 default color palette
...
It is just equally spaced hues around the color wheel, starting from 15:
gg_color_hue <- function(n) {
hues = seq(15, 375, length = n + 1)
hcl(h = hues, l = 65, c = 100)[1:n]
}
For example:
n = 4
cols = gg_color_hue(n)
dev.new(width = 4, height = 4)
plot(1:n, pch = 16, cex = 2, col...
Plot a legend outside of the plotting area in base graphics?
...
10 Answers
10
Active
...
How to sort an array in descending order in Ruby
... Here's what I found out:
#!/usr/bin/ruby
require 'benchmark'
ary = []
1000.times {
ary << {:bar => rand(1000)}
}
n = 500
Benchmark.bm(20) do |x|
x.report("sort") { n.times { ary.sort{ |a,b| b[:bar] <=> a[:bar] } } }
x.report("sort reverse") { n.times ...