## How can i write the frequency vector for frequency range 5-400 hz using 50 frequncy points

Asked by Lisa Justin

### Lisa Justin (view profile)

on 13 Jul 2012
Accepted Answer by Wayne King

### Wayne King (view profile)

How can i write the frequency vector for frequency range 5-400 hz using 50 frequncy points

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### Wayne King (view profile)

Answer by Wayne King

### Wayne King (view profile)

on 13 Jul 2012

Hi Lisa, you cannot have 50 frequencies in 30 elements. Obviously whatever Q is here (is it a power spectral density estimate?) is an estimate at only 30 frequency points.

You can space your frequency vector to cover 5 to 400 Hz with fifty points and then select a subset of those 50 so that you can plot(f,Q)

```freq = linspace(5,400,50);
% just making up some junk data to plot
Q = abs(randn(30,1));
plot(freq(1:30),Q)
```

on 13 Jul 2012
Edited by Ryan

### Ryan (view profile)

on 13 Jul 2012

FrequencyVector = linspace(5,400,50); %linspace(min,max,# of points)

Lisa Justin

### Lisa Justin (view profile)

on 13 Jul 2012
``` f=linspace(5,400,50);
plot(f,Q)
it won't work
Q has a length of 30x1
and f has a length of 1x50
How can i make f 1x30 and still ranging from 5-400 and 50 frequency points```
Ryan

### Ryan (view profile)

on 13 Jul 2012

See Wayne King's answer. These type of details should be included in the original question to provide the best answer possible.

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