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How to slice an array in Bash
...n section in the Bash man page. A[@] returns the contents of the array, :1:2 takes a slice of length 2, starting at index 1.
A=( foo bar "a b c" 42 )
B=("${A[@]:1:2}")
C=("${A[@]:1}") # slice to the end of the array
echo "${B[@]}" # bar a b c
echo "${B[1]}" # a b c
echo "${C...
What is the significance of initializing direction arrays below with given values when developing ch
...what move each index of the arrays will make from the central point, X, at 2,2.)
.....
.536.
.1X0.
.724.
.....
The way it is set up, if you do ^1 (^ being bitwise XOR) on the index you get the opposite direction - 0 and 1 are opposites, 2 and 3 are opposites and so on. (Another way to set it up i...
Converting a list to a set changes element order
...the list, you can do this with a list comprehension:
>>> a = [1, 2, 20, 6, 210]
>>> b = set([6, 20, 1])
>>> [x for x in a if x not in b]
[2, 210]
If you need a data structure that supports both fast membership tests and preservation of insertion order, you can use the k...
How to create a density plot in matplotlib?
...
124
Sven has shown how to use the class gaussian_kde from Scipy, but you will notice that it doesn'...
Remove rows with all or some NAs (missing values) in data.frame
... final[complete.cases(final), ]
gene hsap mmul mmus rnor cfam
2 ENSG00000199674 0 2 2 2 2
6 ENSG00000221312 0 1 2 3 2
na.omit is nicer for just removing all NA's. complete.cases allows partial selection by including only certain columns of the dataframe:
...
PHP: merge two arrays while keeping keys instead of reindexing?
...
You can simply 'add' the arrays:
>> $a = array(1, 2, 3);
array (
0 => 1,
1 => 2,
2 => 3,
)
>> $b = array("a" => 1, "b" => 2, "c" => 3)
array (
'a' => 1,
'b' => 2,
'c' => 3,
)
>> $a + $b
array (
0 => 1,
1 => 2,
2 ...
Difference between '..' (double-dot) and '…' (triple-dot) in range generation?
...
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edited Dec 21 '16 at 0:33
answered Mar 13 '12 at 19:48
...
Pandas DataFrame column to list [duplicate]
...
270
You can use the Series.to_list method.
For example:
import pandas as pd
df = pd.DataFrame({...
LINGO使用指南 - 更多技术 - 清泛网 - 专注C/C++及内核技术
...求解如下的LP问题：
在模型窗口中输入如下代码：
min=2*x1+3*x2;
x1+x2>=350;
x1>=100;
2*x1+x2<=600;
然后点击工具条上的按钮 即可。
例1.2 使用LINGO软件计算6个发点8个收点的最小费用运输问题。产销单位运价如下表。
...
What is the easiest way to push an element to the beginning of the array?
...elf, moving other elements upwards.
And in use:
irb>> a = [ 0, 1, 2]
=> [0, 1, 2]
irb>> a.unshift('x')
=> ["x", 0, 1, 2]
irb>> a.inspect
=> "["x", 0, 1, 2]"
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im...