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How to find whether or not a variable is empty in Bash
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In Bash at least the following command tests if $var is empty:
if [[ -z "$var" ]]; then
# Do what you want
fi
The command man test is your friend.
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Plot correlation matrix into a graph
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Quick, dirty, and in the ballpark:
library(lattice)
#Build the horizontal and vertical axis information
hor <- c("214", "215", "216", "224", "211", "212", "213", "223", "226", "225")
ver <- paste("DM1-", hor, sep="")
#Build the fake correlation matrix
nrowcol <- length(ver)
cor <...
How can the Euclidean distance be calculated with NumPy?
...rvais
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answered Sep 9 '09 at 20:12
u0b34a0f6aeu0b34a0f6ae
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How can I convert an RGB image into grayscale in Python?
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How to slice an array in Bash
...pitone
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answered Aug 26 '09 at 17:10
Paused until further notice.Paused until further notice.
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Hidden Features of JavaScript? [closed]
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@Nathan "f(x,y,z)" looks better than "f([x,y,z])".
– Mark Cidade
Sep 28 '09 at 12:01
16
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Bash if statement with multiple conditions throws an error
... edited Feb 10 '16 at 18:14
BuZZ-dEE
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answered Apr 24 '13 at 22:12
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Converting from longitude\latitude to Cartesian coordinates
...n.bn.
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What is the fastest factorial function in JavaScript? [closed]
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If you still want to calculate the values yourself, you can use memoization:
var f = [];
function factorial (n) {
if (n == 0 || n == 1)
return 1;
if (f[n] > 0)
return f[n];
return f[n] = factorial(n-1) * n;
}
Edit: 21.08.2014
Solution 2
I thought it would be useful to add a w...
Way to get all alphabetic chars in an array in PHP?
Is there a way to get all alphabetic chars (A-Z) in an array in PHP so I can loop through them and display them?
14 Answers...