Q: Problem importing two sparse arrays from a .mat file (Update)
- To: mathgroup at smc.vnet.net
- Subject: [mg107567] Q: Problem importing two sparse arrays from a .mat file (Update)
- From: Claudius Schnörr <Claudius.Schnoerr at gmx.de>
- Date: Wed, 17 Feb 2010 07:03:26 -0500 (EST)
Hello,
how can two sparse arrays be read from a .mat file?
(My Mma version is 7.0.1 on windows)
(The .mat files are version 5)
An example creating some .mat files in the other system:
A = [ 0, 12, 13; 21, 0, 0; 0, 32, 0]; % a (3x3)-matrix
H = sparse(A);
H2 = sparse(A);
save( 'test_A.mat', 'A' ); % file with a dense matrix
save( 'test_H.mat', 'H' ); % file with a sparse matrix
save( 'test_H2.mat', 'H' );
save( 'test_H2.mat', '-append', 'H2' ); % with two sparse matrices
Reading them in Mma:
A = Import["test_A.mat", "Data"][[1]];
MatrixForm[A]
Head[A] (*a List*)
H = Import["test_H.mat", "Data"][[1]];
MatrixForm[H]
Head[H] (*a SparseArray*)
How can multiple sparse arrays be read?
The following doesn't work!
H2 = Import["test_H2.mat", {"Data", {"SparseArray", "SparseArray"}}];
MatrixForm[H2]
Head[H2]
I expected a List of two SparseArrays in H2.
Simply reading by H2=Import["test_H2.mat"] doesn't work either.
Is this a bug or do I use the wrong syntax?
The files can be downloaded here if you can't create the .mat-files
yourself:
http://www.lrz-muenchen.de/~schnoerr/LabCVME/Download/SparseArray_Import.zip
Any help is welcome.
ClS