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

I'm beginning python and I'm trying to use a two-dimensional list, that I initially fill up with the same variable in every place. I came up with this: def initialize_twodlist(foo): twod_list ...

Jun 8, 2014 · It's a good idea to get in the habit of saying list when you mean list and reserving array for numpy ndarray s. There's actually a built-in array module with its own array type, so that confuses …

I want to create an empty array and append items to it, one at a time. xs = [] for item in data: xs.append(item) Can I use this list-style notation with NumPy arrays?

105 If you wish to combine two 10 element one-dimensional arrays into a two-dimensional array, np.vstack((tp, fp)).T will do it. np.vstack((tp, fp)) will return an array of shape (2, 10), and the T …

2 When constructing multi-dimensional lists in Python I usually use something similar to ThiefMaster's solution, but rather than appending items to index 0, then appending items to index 1, etc., I always …

3 If you are concerned about memory footprint, the Python standard library contains the array module; these arrays contain elements of the same type.

I want to create a 2D array of values from the third row based on their x,y coordinates in the file. I read in each column as an individual array, and I created grids of x values and y values using …

Oct 16, 2022 · Using Matplotlib, I want to plot a 2D heat map. My data is an n-by-n Numpy array, each with a value between 0 and 1. So for the (i, j) element of this array, I want to plot a square at the (i, j)

Sep 27, 2013 · Declaring and populating 2D array in python Asked 12 years, 3 months ago Modified 7 years, 9 months ago Viewed 43k times