The procedure plot in Maple accepts three function types: a real function in a single variable expressed as an expression, or a Maple procedure, a parametric function, or a list of points.  If a procedure is being specified, operator notation must be used, that is, the procedure name given without parameters, and the range specified as simply a..b rather than as an equation.

A parametric function has the form . If the option coords=polar is given, the parametric function is interpreted in polar coordinates.  Points will be equally spaced along the interval specified by the range of t in the parametric plot specification.  The points will not be evenly spaced according to the  specified.  The set of lists must contain one undefined variable in it.  If each list contained an undefined variable, then a terminal error would occur.  Hence, all parametric plots must be parametric with respect to the same variable.

A list of points has the form .

w:=proc(x) if x<0 then -x elif (x>0) and (x<4) then x else -x+8 end if end proc: