How to receive a function in MATLAB app DESIGNER given by user in edit field?

HI,

I am working on an app where user will put function and a value .output will be the value we get putting the input value in function.

such as, function will be

y=x^2+2^x+3

and x=2

how to code this??

Answer 1

[Voss]

Something like this would work for functions of one variable, which is always called 'x'

% user inputs:
str = 'x^2+2^x+3'; % function, taken from an EditField
x = 2;             % x value

f = str2func(['@(x)' str])

f = function_handle with value:
    @(x)x^2+2^x+3

y = f(x) % output

y = 11

To be more general than that, you'd have to modify this approach or do something else.

[Himalay Baidya]

Thank you so much.works perfectly.

[Himalay Baidya]

detailed code given below=-----function and a value is taken from user .and when button clicked the result shown in text field.

eq=app.EditField.Value;
            x=app.EditField2.Value;
            

          f = str2func(['@(x)' eq]);
          y = f(x);
         
          app.EditField3.Value=num2str(y);

[Voss]

You're welcome! Glad it's working.

The code you shared just now looks like it will work, assuming:

• app.EditField is an EditField (i.e., a uieditfield of style 'text')
• app.EditField2 is a NumericEditField (i.e., of style 'numeric' - if not, you can use str2double to convert x to a number), and
• app.EditField3 is an EditField (again, of style 'text' - if not, you can avoid converting y to a string with num2str and use the numeric value of y directly).