Accelerating the pace of engineering and science

# Documentation Center

• Trial Software

# upsample

Increase sampling rate by integer factor

## Syntax

y=upsample(x,n)
y=upsample(x,n,phase)

## Description

y = upsample(x,n) increases the sampling rate of x by inserting n-1 zeros between samples. x can be a vector or a matrix. If x is a matrix, each column is considered a separate sequence. The upsampled y has x*n samples.

y = upsample(x,n,phase) specifies the number of samples by which to offset the upsampled sequence. phase must be an integer from 0 to n-1.

## Examples

Increase the sampling rate of a sequence by 3:

```x = [1 2 3 4];
y = upsample(x,3);
x,y
x =
1  2  3  4
y =
1  0  0  2  0  0  3  0  0  4  0  0
```

Increase the sampling rate of the sequence by 3 and add a phase offset of 2:

```x = [1 2 3 4];
y = upsample(x,3,2);
x,y
x =
1  2  3  4
y =
0  0  1  0  0  2  0  0  3  0  0  4
```

Increase the sampling rate of a matrix by 3:

```x = [1 2; 3 4; 5 6;];
y = upsample(x,3);
x,y
x =
1    2
3    4
5    6
y =
1    2
0    0
0    0
3    4
0    0
0    0
5    6
0    0
0    0
```