When I run plot it doesn't show my figure

Hello ,

I have perfome amplitude normalization on my audio file.

I wrote the commade plot() to see the result but nothing appreard.

Also I would like to hear the modified audio file but I'm getting an error.

Please find bellow to code.

[samples,fs] = audioread ('LastDance.wav' );

audiowrite('LastDance.wav', samples,fs);

% pre-processing second part downsampling
S1 = resample(fs,22050,44100);               % downsample from 44100 to 22050

S1peakvalue= max (abs (S1))                  % this commade help us find which is the biggest value on S1
S1_norm = (1/S1peakvalue)*S1                 % we normalize audio file 

figure
plot(S1_norm);

sound(samples,S1_norm);

[Kevin Chng]

check S1_norm, does it contain any value? I guess S1_norm only has 1 value.

try plot

plot(S1)

[Isida Kaloshi]

Hello,

Thank you for your reply.

I tried plot(S1) but I still don't get a result.

What am I doing wrong here?

[Jan]

What does "don't get a result" mean? Something must happen, so please explain, what it is. Do you see one dot, or a line which is zero? Use the debugger to find out, what the contents of S1 is.

It is not clear why you overwrite the file directly after reading it.

[Isida Kaloshi]

Hello,

Actually when a figure open but containing values on x' axis from 0 to 2 and the same for y however nothing else.

Answer 1

[Jan]

You resample the frequency, which is a scalar value, instead of the signal itself:

S1 = resample(fs, 22050, 44100);

You mean:

S1 = resample(samples, 22050, 44100);

[Isida Kaloshi]

Hello,

Actually I want to downsample my signal from 44100 to 22050 and then to perform some amplitude normalization.

S1 = resample(fs,22050,44100); % downsample from 44100 to 22050

% S1peakvalue= max (abs (S1))

% S1_norm = (1/S1peakvalue)*S1

Am I doing it worng?