# 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. 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.