# cat

Concatenate symbolic arrays along specified dimension

## Syntax

``cat(dim,A1,...,AN)``

## Description

example

````cat(dim,A1,...,AN)` concatenates the arrays `A1,...,AN` along dimension `dim`. The remaining dimensions must be the same size.```

## Examples

### Concatenate Two Vectors into Matrix

Create vectors `A` and `B`.

```A = sym('a%d',[1 4]) B = sym('b%d',[1 4])```
```A = [ a1, a2, a3, a4] B = [ b1, b2, b3, b4]```

To concatenate `A` and `B` into a matrix, specify dimension `dim` as `1`.

`cat(1,A,B)`
```ans = [ a1, a2, a3, a4] [ b1, b2, b3, b4]```

Alternatively, use the syntax `[A;B]`.

`[A;B]`
```ans = [ a1, a2, a3, a4] [ b1, b2, b3, b4]```

### Concatenate Two Vectors into One Vector

To concatenate two vectors into one vector, specify dimension `dim` as `2`.

```A = sym('a%d',[1 4]); B = sym('b%d',[1 4]); cat(2,A,B)```
```ans = [ a1, a2, a3, a4, b1, b2, b3, b4]```

Alternatively, use the syntax `[A B]`.

`[A B]`
```ans = [ a1, a2, a3, a4, b1, b2, b3, b4]```

### Concatenate Multidimensional Arrays Along Their Third Dimension

Create arrays `A` and `B`.

```A = sym('a%d%d',[2 2]); A(:,:,2) = -A B = sym('b%d%d', [2 2]); B(:,:,2) = -B```
```A(:,:,1) = [ a11, a12] [ a21, a22] A(:,:,2) = [ -a11, -a12] [ -a21, -a22] B(:,:,1) = [ b11, b12] [ b21, b22] B(:,:,2) = [ -b11, -b12] [ -b21, -b22] ```

Concatenate `A` and `B` by specifying dimension `dim` as `3`.

`cat(3,A,B)`
```ans(:,:,1) = [ a11, a12] [ a21, a22] ans(:,:,2) = [ -a11, -a12] [ -a21, -a22] ans(:,:,3) = [ b11, b12] [ b21, b22] ans(:,:,4) = [ -b11, -b12] [ -b21, -b22]```

## Input Arguments

collapse all

Dimension to concatenate arrays along, specified as a positive integer.

Input arrays, specified as symbolic variables, vectors, matrices, or multidimensional arrays.