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Shortest distance between a point and a line segment
...at l2 = length_squared(v, w); // i.e. |w-v|^2 - avoid a sqrt
if (l2 == 0.0) return distance(p, v); // v == w case
// Consider the line extending the segment, parameterized as v + t (w - v).
// We find projection of point p onto the line.
// It falls where t = [(p-v) . (w-v)] / |w-v|^2
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Reference — What does this symbol mean in PHP?
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How to find the installed pandas version
...ersion__:
In [76]: import pandas as pd
In [77]: pd.__version__
Out[77]: '0.12.0-933-g281dc4e'
Pandas also provides a utility function, pd.show_versions(), which reports the version of its dependencies as well:
In [53]: pd.show_versions(as_json=False)
INSTALLED VERSIONS
------------------
commi...
Add column with constant value to pandas dataframe [duplicate]
...numpy.random import randint
In [9]: df = DataFrame({'a': randint(3, size=10)})
In [10]:
In [10]: df
Out[10]:
a
0 0
1 2
2 0
3 1
4 0
5 0
6 0
7 0
8 0
9 0
In [11]: s = df.a[:5]
In [12]: dfa, sa = df.align(s, axis=0)
In [13]: dfa
Out[13]:
a
0 0
1 2
2 0
3 1
4 0
5 0
6 0
7 0
8 ...
Swift Beta performance: sorting arrays
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tl;dr Swift 1.0 is now as fast as C by this benchmark using the default release optimisation level [-O].
Here is an in-place quicksort in Swift Beta:
func quicksort_swift(inout a:CInt[], start:Int, end:Int) {
if (end - start < 2...
What is the significance of initializing direction arrays below with given values when developing ch
... want to add onto its x and its y value to move it to a nearby location, 1,0 is east, -1,0 is west, 0,1 is south, 0,-1 is north and so on.
(Here I have said top left is 0,0 and bottom right is 4,4 and shown what move each index of the arrays will make from the central point, X, at 2,2.)
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how to convert array values from string to int?
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edited Apr 23 '19 at 10:46
Rahul
16.8k77 gold badges3434 silver badges5353 bronze badges
answered Ma...
Matplotlib scatter plot with different text at each data point
...terating 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 formatting options for annot...
Context switches much slower in new linux kernels
We are looking to upgrade the OS on our servers from Ubuntu 10.04 LTS to Ubuntu 12.04 LTS. Unfortunately, it seems that the latency to run a thread that has become runnable has significantly increased from the 2.6 kernel to the 3.2 kernel. In fact the latency numbers we are getting are hard to belie...
How to extract the decision rules from scikit-learn decision-tree?
... print "{}return {}".format(indent, tree_.value[node])
recurse(0, 1)
This prints out a valid Python function. Here's an example output for a tree that is trying to return its input, a number between 0 and 10.
def tree(f0):
if f0 <= 6.0:
if f0 <= 1.5:
return [[ 0.]]
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