Help with integral2 calculator

I'm trying to create a basic double integral calculator. How do I refine the code I have so far?

      fun = @(x,y) input('enter integrand = ') 
      xmin = @(y) input('enter lower x boundary = ')
      xmax = @(y) input('enter upper x boundary = ')
      ymin = @(x) input('enter lower y boundary = ')
      ymax = @(x) input('enter upper y boundary = ')

      Q = integral2(fun,xmin,xmax,ymin,ymax)

Answer 1

[Star Strider]

Use the str2func (link) function. I would also use vectorize (link):

fun = input('enter integrand = ', 's') 

fun = str2func(['@(x,y) ' vectorize(fun)])

Q = integral2(fun, xmin, xmax, ymin, ymax)

[Star Strider]

As always, my pleasure.

That becomes a bit more complicated, because you must test for a numeric input, and if it’s not numeric, then use str2func:

ymax = input('enter upper y boundary = ','s')
n = str2double(ymax);
if isnan(n)
    ymax = str2func(['@(x) ' vectorize(ymax)]);
else
    ymax = n;
end

You’ll need to do this in each limit, or at least those for which you expect a function input.

[kd]

Thank you so much. You probably saved me 3 days of trial and error.

[Star Strider]

As always, my pleasure!

This is an interesting problem.