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How do you rotate a two dimensional array?
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63 Answers
63
Active
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How to convert floats to human-readable fractions?
Let's say we have 0.33 , we need to output 1/3 .
If we have 0.4 , we need to output 2/5 .
26 Answers
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Index all *except* one item in python
...you could use a list comp. For example, to make b a copy of a without the 3rd element:
a = range(10)[::-1] # [9, 8, 7, 6, 5, 4, 3, 2, 1, 0]
b = [x for i,x in enumerate(a) if i!=3] # [9, 8, 7, 5, 4, 3, 2, 1, 0]
This is very general, and can be used with all iterables, incl...
How to randomize (or permute) a dataframe rowwise and columnwise?
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234
Given the R data.frame:
> df1
a b c
1 1 1 0
2 1 0 0
3 0 1 0
4 0 0 0
Shuffle row-wise:
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Matplotlib scatter plot with different text at each data point
... could use annotate() while iterating over the values in n.
y = [2.56422, 3.77284, 3.52623, 3.51468, 3.02199]
z = [0.15, 0.3, 0.45, 0.6, 0.75]
n = [58, 651, 393, 203, 123]
fig, ax = plt.subplots()
ax.scatter(z, y)
for i, txt in enumerate(n):
ax.annotate(txt, (z[i], y[i]))
There are a lot of...
Adding new column to existing DataFrame in Python pandas
... a b c d
6 -0.269221 -0.026476 0.997517 1.294385
8 0.917438 0.847941 0.034235 -0.448948
>>> df1['e'] = pd.Series(np.random.randn(sLength), index=df1.index)
>>> df1
a b c d e
6 -0.269221 -0.026476 0.997517 ...
pandas: filter rows of DataFrame with operator chaining
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398
I'm not entirely sure what you want, and your last line of code does not help either, but anyw...
Apply a function to every row of a matrix or a data frame
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You simply use the apply() function:
R> M <- matrix(1:6, nrow=3, byrow=TRUE)
R> M
[,1] [,2]
[1,] 1 2
[2,] 3 4
[3,] 5 6
R> apply(M, 1, function(x) 2*x[1]+x[2])
[1] 4 10 16
R>
This takes a matrix and applies a (silly) function to each row. You pass extr...
Is there a simple way to remove multiple spaces in a string?
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Francisco Couzo
8,04633 gold badges2929 silver badges3737 bronze badges
answered Oct 9 '09 at 21:52
Josh LeeJosh Lee
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How do I get indices of N maximum values in a NumPy array?
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365
The simplest I've been able to come up with is:
In [1]: import numpy as np
In [2]: arr = np....