A common problem in many cases is simply selecting a segment to be analyzed,
from a digitized signal file that may include extraneous material at the
beginning or at the end. As you can see from the sqrs example, this can
be done easily by inspecting the signals with WAVE and placing `<'
and `>' markers at the beginning and end of the region of interest. If
the analysis program is written to accept starting and ending times (more on
this subject below), these times can be passed as command-line arguments by
WAVE. Similarly, it's simple to choose one or more of a number of
signals to analyze after viewing them with WAVE (either type into the
Signal field directly, use the increment/decrement buttons, or
point to a
signal in the signal window, press and hold the 
key, and click
left). Close the textedit window and experiment with changing the
Start, End, and Signal fields of the Analyze window, and
running sqrs, until you are familiar with the results.