+ full mat from page 'curves'

doc/Expressions.tex

@@ -157,3 +157,20 @@ is executed as follows:
 \end{lstlisting}
 
 In contrast, a command like \cmd{oz0} or \cmd{op2} or \cmd{oi} implies a loop over ''j'' only.
+
+\subsection{Curves}
+
+Introductory example
+
+\begin{lstlisting}
+ > fm 101 3 testdata                             # create test data set
+0 > =ox (i-50)/10                                 # x-scale now goes from -5 to 5 in steps of 0.1
+0 > =oy exp(-(x-j)^2/2/(1.4^j)^2)*ran(.8,1.2+0*i) # y(x) is now a noisy Gaussian
+0 > cc p0*exp(-(t-p1)^2/2/p2^2)                   # create fit curve
+1 > op0 1                                         # set initial value of fit parameter
+1 > op1 1                                         #   (in this case not really necessary,
+1 > op2 1                                         #   because by default the initial value is 1 anyway)
+1 > cf                                            # perform a fit
+1 > 0,1 p 1                                       # plot spectrum 1 (data and curve)
+0,1 > cp                                          # show fit parameters
+\end{lstlisting}