A simple question about undefined function error

Question

Antonio 2012-10-5

Hello,

Before i ask my question i want to mention that i am beginner level in matlab.

I wrote in matlab a simple program which is given below:

function Problem6I(f,g,x)

plot(x,f,'red',x,g,'cyan');

end

I defined x=linspace(0,40000,40), g=sin(x*pi)+(x.^2)/20 and f=(x.^2)/20 , but I still get this error message:

??? Undefined function or method 'Problem6I' for input arguments of type 'double'.

How can I solve it?

Answer 1

Thomas 2012-10-5

编辑：Thomas 2012-10-5

You are defining it as a function Here is more about declaring functions http://www.mathworks.com/help/matlab/ref/function.html

You could save it as problem6l and then run it

If you use it as a script it should work

 x=linspace(0,40000,40); g=sin(x*pi)+(x.^2)/20 ; f=(x.^2)/20;
 plot(x,f,'red',x,g,'cyan')

Antonio 2012-10-5

The problem is that my homework consists in defining it as a function that must be able to plot every kind of graph.

Thomas 2012-10-5

you need to read about creating functions as described in the link posted about..