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Principal component analysis in Python
...de. 13 years after its first public release, MDP has reached full maturity and no new features are planned in the future.
– Gabriel
Oct 5 '16 at 18:42
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What is an idempotent operation?
...g that x in the mathematical definition represents the state of an object, and f is an operation that may mutate that object. For example, consider the Python set and its discard method. The discard method removes an element from a set, and does nothing if the element does not exist. So:
my_set.dis...
How to modify a global variable within a function in bash?
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When you use a command substitution (ie the $(...) construct), you are creating a subshell. Subshells inherit variables from their parent shells, but this only works one way - a subshell cannot modify the environment of its parent shell. Your v...
What is the 'pythonic' equivalent to the 'fold' function from functional programming?
...u can sometimes use some combination of reduce (from the functools module) and the operator module, e.g.:
def product(xs):
return reduce(operator.mul, xs, 1)
Be aware that reduce is actually a foldl, in Haskell terms. There is no special syntax to perform folds, there's no builtin foldr, and ...
Date ticks and rotation in matplotlib
...sn't do anything, plt.gca() does not give you the axes you want to modify, and so plt.xticks, which acts on the current axes, is not going to work.
For an object-oriented approach not using plt.xticks, you can use
plt.setp( axs[1].xaxis.get_majorticklabels(), rotation=70 )
after the two avail_pl...
Why must a lambda expression be cast when supplied as a plain Delegate parameter
... new delegate type with an appropriate signature, but that's rarely useful and you end up with less opportunity for error checking.
If you want to make it easy to call Control.Invoke with an Action the easiest thing to do is add an extension method to Control:
public static void Invoke(this Contro...
Hidden features of Python [closed]
...ue
In case you're thinking it's doing 1 < x, which comes out as True, and then comparing True < 10, which is also True, then no, that's really not what happens (see the last example.) It's really translating into 1 < x and x < 10, and x < 10 and 10 < x * 10 and x*10 < 100, but...
How do I open the SearchView programmatically?
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Expand the SearchView with
searchView.setIconified(false);
and collapse it with
searchView.setIconified(true);
You need to change the value of android:showAsAction from ifRoom|collapseActionView to always. The SearchView's...
Header files for x86 SIMD intrinsics
...d normally just include <immintrin.h>. It includes everything.
GCC and clang will stop you from using intrinsics for instructions you haven't enabled at compile time (e.g. with -march=native or -mavx2 -mbmi2 -mpopcnt -mfma -mcx16 -mtune=znver1 or whatever.)
MSVC and ICC will let you use int...
Scatterplot with too many points
...+ geom_point(alpha = 0.3)
Another convenient way to deal with this is (and probably more appropriate for the number of points you have) is hexagonal binning:
ggplot(df,aes(x=x,y=y)) + stat_binhex()
And there is also regular old rectangular binning (image omitted), which is more like your tr...