Signal Processing with SMOOTH

A simple way to smooth out the NOISY dataset is to use IDL's SMOOTH function. It returns an array smoothed with a boxcar average of a specified width.

Create a new variable to hold the smoothed dataset by entering the following command:

SMOOTHED=SMOOTH(NOISY, 5)

Now plot your new data set:

IPLOT,SMOOTHED,TITLE='Smoothed Data'

The TITLE keyword draws the title text centered over the plot. Notice that while SMOOTH did a fairly good job of removing noise spikes, the resulting amplitudes taper off as the frequency increases.

Figure 5-4: Using the SMOOTH Command

Figure 5-4: Using the SMOOTH Command