# dot#

## Purpose#

Returns a scalar dot product of the columns of two matrices.

## Format#

z = dot(x, y)#
Parameters:
• x (Nx1 vector or NxK matrix) – first matrix.

• y (Nx1 vector or NxK matrix) – second matrix, y.

Returns:

z (scalar or Kx1) – The dot product of x and y.

## Examples#

### Basic usage#

```// Create two 4x1 column vectors
x = { 5,
9,
3,
4 };

y = { 9,
-6,
8,
1  };

// Compute dot product
z = dot(x, y);

print  "z = " z;
```

After the code above:

```z = 19
```

### Dot product of an Nx1 vector and Nx2 matrix#

```// Create 4x1 vector
x = { 5,
9,
3,
4 };

// Create 4x2 matrix
y = { 9  8,
-6  4,
8  3,
1 -2 };

// Compute dot product
z = dot(x, y);

print  "z = " z;
```

After the code above:

```z = 19
77
```

### Dot product of the corresponding columns of two matrices#

```// Create two 4x2 matrices
x = { 5 1,
9 3,
3 8,
4 2 };

y = { 9  8,
-6  4,
8  3,
1 -2 };

// Compute dot product
z = dot(x, y);

print  "z = " z;
```

After the code above:

```z = 19
40
```

## Remarks#

x and y must have the same number columns, or one of them must only have a single column.