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Mapping two integers to one, in a unique and deterministic way
...sy to define a bijection f : Z -> N, like so:
f(n) = n * 2 if n >= 0
f(n) = -n * 2 - 1 if n < 0
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Pandas: drop a level from a multi-level column index?
...pd.DataFrame([[1,2], [3,4]], columns=cols)
>>> df
a
b c
0 1 2
1 3 4
[2 rows x 2 columns]
>>> df.columns = df.columns.droplevel()
>>> df
b c
0 1 2
1 3 4
[2 rows x 2 columns]
...
Python Infinity - Any caveats?
...-a-number (NaN) values from simple arithmetic involving inf:
>>> 0 * float("inf")
nan
Note that you will normally not get an inf value through usual arithmetic calculations:
>>> 2.0**2
4.0
>>> _**2
16.0
>>> _**2
256.0
>>> _**2
65536.0
>>> _**...
Is there a float input type in HTML5?
...
+50
The number type has a step value controlling which numbers are valid (along with max and min), which defaults to 1. This value is also...
Calculating Pearson correlation and significance in Python
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201
You can have a look at scipy.stats:
from pydoc import help
from scipy.stats.stats import pears...
Can a class member function template be virtual?
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answered Mar 1 '10 at 8:52
sbisbi
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Creating a Pandas DataFrame from a Numpy array: How do I specify the index column and column headers
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350
You need to specify data, index and columns to DataFrame constructor, as in:
>>> pd.Da...
How to turn NaN from parseInt into 0 for an empty string?
Is it possible somehow to return 0 instead of NaN when parsing values in JavaScript?
18 Answers
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Similarity String Comparison in Java
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answered Jun 5 '09 at 9:59
dfadfa
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How is “int* ptr = int()” value initialization not illegal?
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110
int() is a constant expression with a value of 0, so it's a valid way of producing a null pointe...