Questions on the construction and manipulation of sparse arrays in Mathematica, with functions like SparseArray[] and Band[].
13
votes
3answers
414 views
Efficient way to combine SparseArray objects?
I have several SparseArray objects, say sa11, sa12, sa21, sa22, which I would like to combine into the equivalent of {{sa11, sa12}, {sa21, sa22}}.
As an example, I ...
9
votes
2answers
264 views
Speeding up construction of simple tridiagonal matrix
I have the following code to construct a tridiagonal matrix:
...
6
votes
2answers
334 views
Efficient by-element updates to SparseArrays
I have a very large SparseArray called A. What is the most efficient way to update say element ...
5
votes
1answer
36 views
How to relate memory usage with occupied positions of SparseArrays?
What is the relation of memory usage of a SparseArray
and the number of its occupied positions?
Let's say you build a 100.000.000 by 10 element SparseArray.
And fill the two position 1/1 and ...
14
votes
2answers
478 views
Using the Krylov method for Solve: Speeding up a SparseArray calculation
I'm trying to implement this Total Variation Regularized Numerical Differentiation (TVDiff) code in MMA (which I found through this SO answer): essentially I want to differentiate noisy data. The full ...
9
votes
1answer
374 views
Exporting a Large Multidimensional Sparse Array
I'm trying to export a sparse array from Mathematica to share with collaborators who primarily use Matlab.
The sparse array in question is 4 dimensional, (72 x 93 x 94 x 172) with ~4M non-zero ...
5
votes
1answer
143 views
3
votes
3answers
213 views
Support for Compressed Sparse Column sparse matrix representation
Is there native support for Compressed Sparse Column (CSC) format for sparse matrices, like importing and manipulating them?
0
votes
1answer
167 views
Import Excel sheet into 3D array?
I have an excel spreadsheet that I would like to plot in a 3D graph using mathematica. The X and Y values are the location of the cell, and the Z value is the number of the scale.
How can I import ...
