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Grouping functions (tapply, by, aggregate) and the *apply family
... <- matrix(seq(1,16), 4, 4)
# apply min to rows
apply(M, 1, min)
[1] 1 2 3 4
# apply max to columns
apply(M, 2, max)
[1] 4 8 12 16
# 3 dimensional array
M <- array( seq(32), dim = c(4,4,2))
# Apply sum across each M[*, , ] - i.e Sum across 2nd and 3rd dimension
apply(M, 1, sum)
# Result ...
How to get all possible combinations of a list’s elements?
... list with 15 numbers in, and I need to write some code that produces all 32,768 combinations of those numbers.
27 Answers...
How to drop rows of Pandas DataFrame whose value in a certain column is NaN
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12 Answers
12
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Get distance between two points in canvas
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211
You can do it with pythagoras theorem
If you have two points (x1, y1) and (x2, y2)
then you c...
Numpy - add row to array
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122
What is X? If it is a 2D-array, how can you then compare its row to a number: i < 3?
EDIT a...
How do I declare and initialize an array in Java?
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28 Answers
28
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How to check if hex color is “too black”?
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227
You have to extract the three RGB components individually, and then use a standard formula to ...
finding and replacing elements in a list
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266
>>> a= [1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1]
>>> for n, i in enumerate(a):
... ...
get list from pandas dataframe column
...st it with list(x).
import pandas as pd
data_dict = {'one': pd.Series([1, 2, 3], index=['a', 'b', 'c']),
'two': pd.Series([1, 2, 3, 4], index=['a', 'b', 'c', 'd'])}
df = pd.DataFrame(data_dict)
print(f"DataFrame:\n{df}\n")
print(f"column types:\n{df.dtypes}")
col_one_list = df['one'...
The $.param( ) inverse function in JavaScript / jQuery
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62
You should use jQuery BBQ's deparam function. It's well-tested and documented.
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