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How to convert Nonetype to int or string?
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10 Answers
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Android phone orientation overview including compass
...ow I think (hope) I have a better feeling for it again but I am still not 100%. I will try and explain my patchy understanding of it and hopefully people will be able to correct me if I am wrong in parts or fill in any blanks.
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How to format a Java string with leading zero?
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In case you have to do it without the help of a library:
("00000000" + "Apple").substring("Apple".length())
(Works, as long as your String isn't longer than 8 chars.)
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impro...
Why is isNaN(null) == false in JS?
...false.
So in the specific case x = null, null is converted to the number 0, (try evaluating Number(null) and see that it returns 0,) and isNaN(0) returns false. A string that is only digits can be converted to a number and isNaN also returns false. A string (e.g. 'abcd') that cannot be converted t...
How is a CRC32 checksum calculated?
...e polynomial for CRC32 is:
x32 + x26 + x23 + x22 + x16 + x12 + x11 + x10 + x8 + x7 + x5 + x4 + x2 + x + 1
Wikipedia
CRC calculation
Or in hex and binary:
0x 01 04 C1 1D B7
1 0000 0100 1100 0001 0001 1101 1011 0111
The highest term (x32) is usually not explicitly written, so it can i...
What characters are valid for JavaScript variable names?
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1000
+50
To quot...
How to get the type of a variable in MATLAB?
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answered Feb 23 '09 at 17:36
Daniel LeCheminantDaniel LeCheminant
47.3k1515 gold badges115115 silver badges113113 bronze badges
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adding noise to a signal in python
I want to add some random noise to some 100 bin signal that I am simulating in Python - to make it more realistic.
7 Answer...
Group by multiple columns in dplyr, using string vector input
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data = data.frame(
asihckhdoydkhxiydfgfTgdsx = sample(LETTERS[1:3], 100, replace=TRUE),
a30mvxigxkghc5cdsvxvyv0ja = sample(LETTERS[1:3], 100, replace=TRUE),
value = rnorm(100)
)
# get the columns we want to average within
columns = names(data)[-3]
library(dplyr)
df1 <- data %>%...
Deleting an element from an array in PHP
...t() which will convert all keys to numerical enumerated keys starting from 0.
Code
<?php
$array = [0 => "a", 1 => "b", 2 => "c"];
unset($array[1]);
//↑ Key which you want to delete
?>
Output
[
[0] => a
[2] => c
]
\array_splice() method
If yo...