All Questions
Tagged with vectorization matrix
6 questions
3
votes
1
answer
233
views
Vectorizing matrix operation instead of for loop in circular matrices
I have a vector \$X_k\$ and a matrix \$Y_{k,j}\$, where \$k \in \{1,\dots,K\}\$ and \$j \in \{1, \dots, J\}\$. They are circular, meaning that $$\eqalign{X_{k+K} &= X_k \\ Y_{k+K,j} &= Y_{k,j} ...
- 197
1
vote
1
answer
140
views
Horizontally concatenating the entries of two matrices, and padding with NaNs
I have two matrices a and b that have, on each line, some values (null or not) and then a bunch of zeros at the end.
I want to ...
- 294
5
votes
2
answers
98
views
Extract the largest value for each day from a matrix
I have a matrix in which the right-most elements are repeated YYYYMMDD dates in descending order, for example:
...
- 2,067
1
vote
1
answer
127
views
Merging two square matrices
I would like to optimize a snippet of code, which uses a multiple nested if statements. I am looking for a formula to make it as a combination of multiple arrays ...
user21479
2
votes
1
answer
434
views
Optimize matlab triple for loop
I have a large matrix samples, I want to make another matrix sampleProb which is the same size, but modified as below:
...
- 131
3
votes
1
answer
87
views
Fast counting of interactions between groups given users interactions and groups assignments
Given:
An array c that contains the group assignment of every user (c[i]=4 indicates that user i belongs to group 4)
A matrix ...
- 235