Add documentation in header.

src/utilities/dplot/dplot.m

@@ -12,6 +12,12 @@ function dplot(varargin)
 % Will produce plots of 2*cumsum(x/y(-1)-1), where x and y are variables in objects toto and noddy,
 % in the same figure.
 %
+% INPUTS
+% --expression    followed by a mathematical expression involving variables available in the dseries objects, dseries methods, numbers or parameters.
+% --dseries       followed by the name of a dseries object available in the workspace.
+% --range         followed by a dates range
+% --with-legend   prints a legend below the produced plot.
+%
 % REMARKS
 % [1] More than one --expression argument is allowed
 % [2] --expression arguments must come first