s</tt> block. Each line in the block
 specifies one function. The first element of each line will be a string
 that defines the name of the function. The second element specifies which type
 of function we are using; in the following we provide an example for each of the
 possible types:
<br><br>
    (1) <tt>tdf_cw</tt>
<br><br>
 <tt>%TDFunctions
 <br>&nbsp;&nbsp; "function-name" | tdf_cw | amplitude
 <br>%</tt>
<br><br>
 The function is just a constant of value <tt>amplitude</tt>.
<br><br>
 <math> f(t) = a