Jul 12, 2011 · I want to define a two-dimensional array without an initialized length like this: Matrix = [][] But this gives an error: IndexError: list index out of range

Oct 23, 2014 · There have been a couple questions on SO about how to initialize a 2-dimensional matrix, with the answer being something like this: matrix = [[0 for x in range(10)] for x in …

Dec 17, 2017 · If your matrix is already created and thus an item already exists in row i and column j you can modify that item with A[i][j] = newvalue This works for the various "matrices" …

Jan 29, 2015 · If you're doing numerical work with matrices, you may want to look at numpy.

I simply want to create an empty 10*3*2 array with Python. I first thought of these one, but this is not working: parameters = [ [ [] * 2 ]*3 ] * 10 this gives me a vector of ten vectors, with th...

May 20, 2012 · I define an array like this: new_array= numpy.zeros ( (6340,200,200)) but it tooks a space of 1.9GB at memory. Is it normal?

Oct 3, 2009 · A couple of contributions suggested that arrays in python are represented by lists. This is incorrect. Python has an independent implementation of array() in the standard library …

I am trying to define a float matrix using this code in python 2.7: import numpy as np A=np.array ( [ [1/16,1/8,1/16], [1/8,1/4,1/8]]) print A The result matrix is a floor value matrix (int value mat...

Oct 26, 2017 · I want to use a matrix in my Python code but I don't know the exact size of my matrix to define it. For other matrices, I have used np.zeros(a), where a is known. What should …

Sep 12, 2017 · I have calculated 9 matrix elements named sij, with i and j being variables (i,j = [1, 2, 3]). Here, i denotes rows and j columns. Suppose I want a 3x3 matrix that consists of the …