converts an expression to a string
t = sci2exp(a [,nam] [,lmax])
a scilab expression, may be:
a constant;
a polynomial;
a string matrix;
a list;
a boolean matrix;
a handle (only figure and uicontrol).
a character string.
a vector of strings, contains the expression or the affectation instruction.
an integer, contains the maximum line length. Default
value is 0,
which indicates no line length
control; a single string is returned.
sci2exp converts expression to an instruction string if nam is
given or to an expression string.
If a is a handle, sci2exp gives a result which has no hierarchical links,
that is, with empty fields for parent and children.
t can be impacted by format.