The numpy docs recommend using array instead of matrix for working with matrices. However, unlike octave (which I was using till recently), * doesn’t perform matrix multiplication, you need to use the function matrixmultipy(). I feel this makes the code very unreadable.
So I am wondering if there’s a more efficient solution in generating a 2-D array using np.random.choice where each row has unique values.
I would like to create a two dimensional numpy array of arrays that has a different number of elements on each row.
I need to find the index of the first value in a 1d NumPy array, or Pandas numeric series, satisfying a condition. The array is large and the index may be near the start or end of the array, or the condition may not be met at all. I can’t tell in advance which is more likely. If the condition is not met, the return value should be -1. I’ve considered a few approaches.
import numpy as np data = np.arange(-50,50,10) print data [-50 -40 -30 -20 -10 0 10 20 30 40] I want to repeat each element of data 5 times and make new array as follows: ans = [-50 -50 -50 -50 -50 -40 -40 … 40] How can I do it? What about repeating the … Read more
I want to know how I can pad a 2D numpy array with zeros using python 2.6.6 with numpy version 1.5.0. But these are my limitations. Therefore I cannot use np.pad. For example, I want to pad a with zeros such that its shape matches b. The reason why I want to do this is so I can do:
Following this answer to “Can I force a numpy ndarray to take ownership of its memory?” I attempted to use the Python C API function PyArray_ENABLEFLAGS through Cython’s NumPy wrapper and found it is not exposed.
Say I have a bunch of numbers in a numpy array and I test them based on a condition returning a boolean array:
After doing some processing on an audio or image array, it needs to be normalized within a range before it can be written back to a file. This can be done like so:
I wonder, how to save and load numpy.array data properly. Currently I’m using the numpy.savetxt() method. For example, if I got an array markers, which looks like this: