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# unpack

Uncompress a list of block-diagonal symmetric matrices.

### Syntax

`A=unpack(CA,blocksizes)`

### Arguments

CA

p-by-n real matrix of doubles, a compressed representation of `A`.

blocksizes

b-by-1 real matrix of doubles, the sizes of the blocks.

A

m-by-n real matrix of doubles, the entries of a list of block-diagonal symmetric matrices. n is the number of matrices stored into `A`.

### Description

This function is the reverse of the `pack` function. It uncompresses a list of symmetric block-diagonal matrices which have been compressed by `pack`.

### Examples

```// Define a compressed list of symmetric block-diagonal matrices.
// There are 3 matrices in the list, as indicated by the 3 columns in CA.
// Only the nonzero entries are stored in CA.
// Only the upper part of the symmetric diagonal matrices are stored in CA.
CA = [
2,1,2;
1,2,2;
2,1,2;
3,1,3;
1,3,4;
3,1,4
]
// Each of the 3 block-diagonal matrices has 2 blocks.
// Define the size of the two blocks:
// the first block has size 2,
// the second block has size 2.
blocksizes=[2,2];
// Unpack the matrices.
A=unpack(CA,blocksizes)```

### See also

• pack — Compress a list of block-diagonal symmetric matrices.
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