diag2vec {OpenMx} | R Documentation |

## Extract Diagonal of a Matrix

### Description

Given an input matrix, `diag2vec`

returns a column vector of the elements along the diagonal.

### Usage

```
diag2vec(x)
```

### Arguments

### Details

Similar to the function `diag`

, except that the input argument is always
treated as a matrix (i.e., it doesn't have diag()'s functions of returning an Identity matrix from an nrow specification, nor to return
a matrix wrapped around a diagonal if provided with a vector). To get vector2matrix functionality, call `vec2diag`

.

### See Also

`vec2diag`

### Examples

```
diag2vec(matrix(1:9, nrow=3))
# [,1]
# [1,] 1
# [2,] 5
# [3,] 9
diag2vec(matrix(1:12, nrow=3, ncol=4))
# [,1]
# [1,] 1
# [2,] 5
# [3,] 9
```

[Package

*OpenMx* version 2.21.11

Index]