Calling a function from another function

The first function is as below:

function my_first_function1(input,b)

c = input*b;

absx = c;

absx

end

The second function calling the first function is below:

function my_first_subfunction(a)

input = 2;

d = my_first_function1(input,b);

out = d +a;

out

end

Error:

>> my_first_subfunction(a)

Unrecognized function or variable 'b'.

Error in my_first_subfunction (line 3)

d = my_first_function1(input,b);

Answer 1

[James Tursa]

my_first_function1( ) doesn't return any value to the caller. To return a value you use this syntax:

function absx = my_first_function1(input,b)
c = input*b;
absx = c;
absx
end

my_first_subfunction( ) uses variable b before it is defined. Examine the code for this function and you will see that there is nothing in the function that defines b before it is used as an input argument to another function.

[JITHIN NALUPURAKKAL]

Thanks for the answer. But b has already been defined in my workspace as

b =

-0.5000 0.2500 0.2500

-3.0000 2.5000 -0.5000

2.5000 -1.7500 0.2500

[Steven Lord]

It may exist in the base workspace, but it does not exist in the workspace of your my_first_subfunction function. See this documentation page for a brief description of the difference.

[JITHIN NALUPURAKKAL]

Thanks. But the first function had used the base workspace while executing the calculation. i.e while calling the first function i used my_first_function1(2,b). So 'input' being 2 and 'b' was extracted from the base workspace.

[Steven Lord]

So 'input' being 2 and 'b' was extracted from the base workspace.

No.

The main way variables get from the base workspace to a function workspace is by being passed into the function when it is called from the base workspace. If one function B is being called from another function A then A can pass variables from its workspace into B by specifying them as input arguments. But neither A's workspace nor B's workspace automatically has access to the base workspace. [While there are ways for them to access the base workspace, generally speaking we discourage the use of the functions that you would need to explicitly use to do that.]

If you want your function B called from function A to have access to data from the base workspace, you will need to pass it into A's workspace as an input argument so A has access to it and can pass it into B.

[JITHIN NALUPURAKKAL]

function [absx,absy] = my_first_function1(input,b)

c = input*b;

d = inv(c);

absx = c;

absy = d;

absx

absy

end

function my_first_subfunction(input,b,absx,absy)

input = 3;

b = [1 2 4; 3 4 6; 4 2 3];

d = my_first_function1(input,b);

disp('b incomin')

z = absx;

y = absy;

disp(z);

disp(y);

end

>> my_first_subfunction

absx =

3 6 12

9 12 18

12 6 9

absy =

-0.0000 -0.0667 0.1333

-0.5000 0.4333 -0.2000

0.3333 -0.2000 0.0667

b incomin

Not enough input arguments.

Error in my_first_subfunction (line 6)

z = absx;

[JITHIN NALUPURAKKAL]

Really appreciate your insight.

I tried this way. But even though am passing the return to "my_first_subfunction", its not taking the variables absx and absy from "my_first_function1".