# cat

Concatenate symbolic arrays along specified dimension

## 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.

## Version History

Introduced in R2010b

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