DCT function plot - spectral frequency

[Cuchara]

Hi all,

I want to take an audio file (WAV) and make to him the cosine transform.
Because that isn't a image file I use the 1D dct function.

The question is, if I want to plot the result - it's a normal plot? How could I know wich axis I recieve at the normal plot of the dct? And, I still how can I see the spectral frequencies of the DCT? I use Matlab..

Thanks all

 

[reza523573]

Hello.you can use MATLAB help. DCT is a rough command and you can plot result by "plot function". note that dct has real outputs and symmetric around n=0.

Bye

 

[Cuchara]

Ok, regarding the plot it's like a normal function.
My doubt is about the axis of the dct. As I understand from the matlab help and so on, it supposed to be Frequency - Amplitude (X - Y).
But when I plot it it appear like Samples - Amplitude, how can I display it as Frequency x axis???

I'm really get confused..

Tanxs