MaplePrimes - answers and comments on Question, Help with plotting

Return unevaluated

Preben Alsholm — Sun, 27 Jan 2013 21:38:56 Z

plot evaluates its arguments first (as most Maple procedures do). So pltx(2, 5, x) is evaluated. But x is just a name. So obviously the inequality checks in pltx cannot succeed.

Either use unevaluation quotes around pltx(2, 5, x) as in:

d := plot('pltx(2, 5, x)', x = 0.1 .. 0.4);

or change the procedure so it begins like this

pltx := proc (num1::integer, num2::integer, x)
if not x::numeric then return 'procname(_passed)' end if;
#The rest unchanged

This will mean that

pltx(2, 5, x);

returns unevaluated, if x is not of type numeric.

piecewise

Carl Love — Mon, 28 Jan 2013 01:08:39 Z

Preben's answer is great, and it will work for procedures in general. I just want to direct you to a great command that is made especially for your kind of function: It's called ?piecewise.

Thank you

splatcat — Mon, 28 Jan 2013 00:26:27 Z

Great help and worked perfectly :) Saved me hours :)