I need to calculate time-evolving power spectral density using Matlab periodogram function

It still doesn't give me the result needed. Actually I need to show the variations of one signal component on time scale. I first, filtered the data at certain frequency, then I apply moving boxcar filter with the overlap of 85% and then calculate time evolving PSD using Matlab periodogram based on Welch theory. I need to plot PSD on the same time scale as original signal. After all of this I am now completely confused. Please help.

[Wayne King]

You have an active thread:

http://www.mathworks.com/matlabcentral/answers/67421-i-need-to-calculate-time-evolving-power-spectral-density-using-matlab-periodogram-function

Please do not keep creating new threads -- this is the second, for the same topic.

Welch's estimate is not the periodogram.

I've tried to help you in your original post.