Tagged Questions
1
vote
1answer
34 views
numpy applying aggregated information across a 2D array
i have a list of agent's "health" in a 2D array:
health=[[0.5,0.8],[0.1,0.5],[0.5,0.7]]
and a set of actions( one per agent):
actions=[[0,1],[2,0],[1,1]]
(possible actions = {0,1,2}
depending ...
2
votes
1answer
84 views
Convert 2-d array of strings to float in python_removing scientific notation
How can I convert scientific notations to the original format when I use numpy.astype in x array? Here's my code:
with open ('outfile.csv', 'r') as infile:
reader = csv.reader(infile)
...
3
votes
1answer
99 views
Can't reshape numpy array
I have a function that is supposed to take a 1D array of integers and shapes it into a 2D array of 1x3 arrays. It then is supposed to take each 1x3 array and shift it into a 3x1 array. The result is ...
0
votes
2answers
63 views
List of 3x1 numpy arrays in Python
I'm trying to write a python function that will take a 1D array of RGB values and make a list of 3x1 arrays that represent pixels. Here is my function
def RGBtoLMS(rgbValues, rgbLength): #Passing in ...
0
votes
1answer
661 views
Python Index error (out of bounds) accessing element in 2D array
I'm trying to access an element of a 2d array created from data in a csv file. I can print the array fine.
When I try to access the array to find a certain element (i.e. a number from 'row' 1 ...
3
votes
2answers
146 views
iterating over numpy arrays
I am having a very difficult time vectoring, I can't seem to think about math in that way yet. I have this right now:
#!/usr/bin/env python
import numpy as np
import math
grid = np.zeros((2,2))
...
2
votes
1answer
157 views
numpy: 1d histogram based on 2d-pixel euclidean distance from center
I am using python, with scipy, numpy, etc.
I want to compute the histogram of intensity values of a grayscale image, based on the distance of the pixels to the center of mass of the image. The ...
2
votes
1answer
157 views
Using a condition to plot with matplotlib
I have a 2-D array and I need to plot columns x and y but only within a certain range of x.
I know how to plot using the index but I need to specify the value of x. I have a few of those arrays so I ...
9
votes
4answers
411 views
Sum between pairs of indices in 2d array
Sorry, I do not know the protocol for re-asking a question if it doesn't get an answer. This question was asked a few months ago here: Numpy sum between pairs of indices in 2d array
I have a 2-d ...
2
votes
2answers
130 views
How to create a Numpy 2d array with equal difference between rows?
How can I create a (48,64) Numpy array like this:
i, i, i, .....,i
i+0.1, i+0.1,..........,i+0.1
i+0.2, i+0.2,..........,i+0.2
.
.
.
.
i+6.3, i+6.3,..........,i+6.3
0.1 is the fixed ...
1
vote
1answer
378 views
Numpy sum between pairs of indices in 2d array
I have a 2-d numpy array (MxN) and two more 1-d arrays (Mx1) that represent starting and ending indices for each row of the 2-d array that I'd like to sum over. I'm looking for the most efficient way ...
2
votes
3answers
566 views
Manipulating indices to 2d numpy array
I can index a 2d numpy array with a tuple or even a list of tuples
a = numpy.array([[1,2],[3,4]])
i = [(0,1),(1,0)] # edit: bad example, should have taken [(0,1),(0,1)]
print a[i[0]], a[i]
(Gives 2 ...
5
votes
1answer
4k views
numpy - 2d array indexing
According to docs numpy's default behaviour is to index arrays first by rows then by columns:
a = numpy.arange(6).reshape(3,2)
[[0 1]
[2 3]
[4 5]]
print a[0][1] # is 1
I want to index the array ...
