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List of lists into numpy array
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How fast is this with respect to the length of the argument? I am not seeing a good answer in the documentation?
– Czarking
Aug 5 at 0:54
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What and where are the stack and heap?
...ocator requests more memory from the operating system).
What makes one faster?
The stack is faster because the access pattern makes it trivial to allocate and deallocate memory from it (a pointer/integer is simply incremented or decremented), while the heap has much more complex bookkeeping in...
What is the best open-source java charting library? (other than jfreechart) [closed]
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For dynamic 2D charts, I have been using JChart2D. It's fast, simple, and being updated regularly. The author has been quick to respond to my one bug report and few feature requests. We, at our company, prefer it over JFreeChart because it was designed for dynamic use, unlike JFre...
How to auto-indent code in the Atom editor?
...approach restores the original selection when it's done (and it happens so fast, you don't even notice the selection was ever changed).
1.) First, add a custom command to your init script (File->Open Your Init Script, then paste this at the bottom):
atom.commands.add 'atom-text-editor', 'custom...
document.getElementById vs jQuery $()
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Do you happen to know which one is faster - $(document.getElementById('element')) vs $('#element')?
– Ivan Ivković
Jan 18 '13 at 7:49
10
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git undo all uncommitted or unsaved changes
...one from original source (but it does not re-download anything, so is much faster):
git reset
git checkout .
git clean -fdx
Typical usage for this would be in build scripts, when you must make sure that your tree is absolutely clean - does not have any modifications or locally created object file...
Live-stream video from one android phone to another over WiFi
...next image from the host. Since you are on wifi that communication will be fast enough to get around 8-10 images per-second(approximation only, i worked on Bluetooth). So this will look like a continuous video but with much less effort.
For communication you may use UDP sockets(Faster and less comp...
Very large matrices using Python and NumPy
...ndy when dealing with tens or hundreds of millions of rows. It's also very fast; my 5 year old laptop can crunch through data doing SQL-like GROUP BY aggregation at 1,000,000 rows/second. Not bad for a Python-based solution!
Accessing the data as a NumPy recarray again is as simple as:
data = tabl...
Modifying a subset of rows in a pandas dataframe
...df = pd.DataFrame(np.random.randint(0,3, (100000,2)), columns=list('ab'))
Fast solution with numpy.where
df['b'] = np.where(df.a.values == 0, np.nan, df.b.values)
Timings
%timeit df['b'] = np.where(df.a.values == 0, np.nan, df.b.values)
685 µs ± 6.4 µs per loop (mean ± std. dev. of 7 runs, 100...
Why doesn't JavaScript have a last method? [closed]
...of ES5, but it's good enough to know now as browsers are catching up to it fast, including IE9.
– Anurag
Jul 13 '10 at 8:49
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