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How to add an extra column to a NumPy array
...lution and faster to boot is to do the following:
import numpy as np
N = 10
a = np.random.rand(N,N)
b = np.zeros((N,N+1))
b[:,:-1] = a
And timings:
In [23]: N = 10
In [24]: a = np.random.rand(N,N)
In [25]: %timeit b = np.hstack((a,np.zeros((a.shape[0],1))))
10000 loops, best of 3: 19.6 us per ...
Find row where values for column is maximal in a pandas DataFrame
...,3),columns=['A','B','C'])
>>> df
A B C
0 1.232853 -1.979459 -0.573626
1 0.140767 0.394940 1.068890
2 0.742023 1.343977 -0.579745
3 2.125299 -0.649328 -0.211692
4 -0.187253 1.908618 -1.862934
>>> df['A'].argmax()
3
>>> df['B'].argmax()
4
&...
Get statistics for each group (such as count, mean, etc) using pandas GroupBy?
... counts
– alvitawa
Jun 24 '19 at 16:04
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Are list-comprehensions and functional functions faster than “for loops”?
...el loop:
>>> dis.dis(<the code object for `[x for x in range(10)]`>)
1 0 BUILD_LIST 0
3 LOAD_FAST 0 (.0)
>> 6 FOR_ITER 12 (to 21)
9 STORE_FAST 1 (x)
12 LOAD_FAST...
How to use a decimal range() step value?
Is there a way to step between 0 and 1 by 0.1?
33 Answers
33
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Linear Regression and group by in R
...ual time series with one field for year (22 years) and another for state (50 states). I want to fit a regression for each state so that at the end I have a vector of lm responses. I can imagine doing for loop for each state then doing the regression inside the loop and adding the results of each reg...
How does the Brainfuck Hello World actually work?
...
+100
1. Basics
To understand Brainfuck you must imagine infinite array of cells initialized by 0 each.
...[0][0][0][0][0]...
When brai...
How to change the order of DataFrame columns?
...ged as needed.
This is what you have now:
In [6]: df
Out[6]:
0 1 2 3 4 mean
0 0.445598 0.173835 0.343415 0.682252 0.582616 0.445543
1 0.881592 0.696942 0.702232 0.696724 0.373551 0.670208
2 0.662527 0.955193 0.131016 0.609548 0.8046...
How can I profile C++ code running on Linux?
...
1440
If your goal is to use a profiler, use one of the suggested ones.
However, if you're in a hurry...
What is the difference between NULL, '\0' and 0?
...ear to be differences between various values of zero -- NULL , NUL and 0 .
11 Answers
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