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Complex numbers usage in python [closed]
...suffix comes from electrical engineering, where the variable ‘i’ is usually used for current. (Reasoning found here.)
The type of a complex number is complex, and you can use the type as a constructor if you prefer:
>>> complex(2,3)
(2+3j)
A complex number has some built-in accesso...
passing several arguments to FUN of lapply (and others *apply)
...e, we find the following line:
...: optional arguments to ‘FUN’.
So all you have to do is include your other argument in the lapply call as an argument, like so:
lapply(input, myfun, arg1=6)
and lapply, recognizing that arg1 is not an argument it knows what to do with, will automatically p...
What is the C++ function to raise a number to a power?
... long double version it should take, and you would get an ambiguity error. All three would need a conversion from int to floating point, and all three are equally costly!
Therefore, be sure to have the first argument typed so it matches one of those three perfectly. I usually use double
pow(2.0, ...
How do I get a substring of a string in Python?
...o Worl'
>>> x[-2:]
'd!'
>>> x[2:-2]
'llo Worl'
Python calls this concept "slicing" and it works on more than just strings. Take a look here for a comprehensive introduction.
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List comprehension on a nested list?
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This seems to be the one explanation that's actually hitting home with me, thank you!
– Douglas Plumley
Mar 20 at 2:33
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Is It Possible to Sandbox JavaScript Running In the Browser?
...vaScript running in the browser to prevent access to features that are normally available to JavaScript code running in an HTML page.
...
Finding local IP addresses using Python's stdlib
... This example has an external dependency of being able to actually resolve gmail.com. If you set it to an ip address that is not on your local lan (doesn't matter if it's up or down) it'll work without dependencies and without network traffic.
– grim
...
Change R default library path using .libPaths in Rprofile.site fails to work
I am running R on Windows, not as an administrator. When I install a package, the following command doesn't work:
15 Answer...
Linux equivalent of the Mac OS X “open” command [closed]
...f diagnostics and warnings right into your terminal (even though nothing really went wrong). I usually have to do something like xdg-open <file> &> /dev/null & instead. Is there anything better than xdg-open in this regard?
– Suan
Nov 30 '11 at...
What is the role of the bias in neural networks? [closed]
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I think that biases are almost always helpful. In effect, a bias value allows you to shift the activation function to the left or right, which may be critical for successful learning.
It might help to look at a simple example. Consider this 1-input, 1-output network that has no bias:
The ou...