specplot(t,x,2*pi./fs,w);</tt> where <tt>t</tt> is the time axis and <tt>x</tt> is your data.
7. Try different colormaps including <tt>colormap lansey</tt>.
1. Repeat step #1 with larger value <tt>beta</tt>=10, or other values of your choice.  <tt>beta</tt> should be greater than or equal to 1/2.
1. The `$y$`-axis here is in periods.  Make sure that you have it in physical units, e.g. days or hours.
1. Repeat steps #1 and #3 but with the time series being an array of zeros of the same length as your data, w