Error "Undefined function or variable"

I defined a function;

function [maBar, wBar, alphaBar] = hcEqPt(vBar, c1, c2, c3, c4)

wBar = vBar/0.129;

maBar = (36.6 + 0.106*wBar + c4*(wBar^2))/c3;

alphaBar = (acos(1-(c2*wBar*maBar/c1)) + 0.0252)/ 1.14;

end

[maBar_1, wBar_1, alphaBar_1] = hcEqPt(22, 0.6, 0.095, 47500, 0.0026);

disp("At v=22, ma = %d, w = %d, alpha = %d", maBar_1, wBar_1, alphaBar_1);

When I try to use this function to obtain a values of vBar further in the script it shows an error "Undefined function or variable".

Kindly help.

Answer 1

[madhan ravi]

[maBar_1, wBar_1, alphaBar_1] = hcEqPt(22, 0.6, 0.095, 47500, 0.0026);

fprintf('At v=22, ma = %d, w = %d, alpha = %d', maBar_1, wBar_1, alphaBar_1);

function [maBar, wBar, alphaBar] = hcEqPt(vBar, c1, c2, c3, c4)

wBar = vBar/0.129;
maBar = (36.6 + 0.106*wBar + c4*(wBar^2))/c3;
alphaBar = (acos(1-(c2*wBar*maBar/c1)) + 0.0252)/ 1.14;
end

[madhan ravi]

function definition should be at the end of the file when you use it in a script file: https://in.mathworks.com/help/matlab/ref/function.html#description

[Shikhar Sharma]

Hey I tried what you mentioned above,

[maBar_1, wBar_1, alphaBar_1] = hcEqPt(22, 0.6, 0.095, 47500, 0.0026);

fprintf("At v=22, ma = %d, w = %d, alpha = %d", maBar_1, wBar_1, alphaBar_1);

function [maBar, wBar, alphaBar] = hcEqPt(vBar, c1, c2, c3, c4)

wBar = vBar/0.129;

maBar = (36.6 + 0.106*wBar + c4*(wBar^2))/c3;

alphaBar = (acos(1-(c2*wBar*maBar/c1)) + 0.0252)/ 1.14;

end

But it still shows undefined function or variable 'hcEqPt'.

[madhan ravi]

Hey what version are you using?? It works for me without a flaw. If you’re using version prior to 2016b save the function in a separate file , the name of the file should be in the name of the function.

[Shikhar Sharma]

Iam using 2019a.

[madhan ravi]

Could you share a screenshot of the script file?

[Shikhar Sharma]

[madhan ravi]

Man you have some serioud problems in just copying properly. Did you even read the answer properly?? THE FUNCTION DEFINITION SHOULD BE AT THE END OF THE FILE!!!

[Shikhar Sharma]

Relax man, I'm quite new to this and trying to learn.

Also, I did remove the function from the beginning of the file and ran the code. But it still shows the error I mentioned above.

[madhan ravi]

Paste the screenshot of the one with the changes you made. Those wiggly orange and red lines are not for decorations hover the mouse over it (it'll display the warning).

[Shikhar Sharma]

[madhan ravi]

Copy the below and paste it in a new file named Shikhar.m and run the code , let's see if that triggers any errors.

[maBar_1, wBar_1, alphaBar_1] = hcEqPt(22, 0.6, 0.095, 47500, 0.0026);
fprintf('At v=22, ma = %d, w = %d, alpha = %d', maBar_1, wBar_1, alphaBar_1);

function [maBar, wBar, alphaBar] = hcEqPt(vBar, c1, c2, c3, c4)
wBar = vBar/0.129;
maBar = (36.6 + 0.106*wBar + c4*(wBar^2))/c3;
alphaBar = (acos(1-(c2*wBar*maBar/c1)) + 0.0252)/ 1.14;
end

[Shikhar Sharma]

This works perfectly fine.

I think the problem is clear roots.

[madhan ravi]

You can remove that line , sir Walter and I suggested in your previous question is because you had defined roots as a variable somewhere so once you clear it from workspace it would'nt be a problem. You can just hover the mouse to that red line and see what message MATLAB displays there (this is only if you're curious to prevent it in the future.) Once you figure it out please do share the solution.

[Shikhar Sharma]

To be honest, I had not defined roots anywhere before in the file. When I remove it, the error moves to the next line and happens subsequently.

[madhan ravi]

https://in.mathworks.com/matlabcentral/answers/479467-error-undefined-function-or-variable#comment_743649 - this is the basic reason causing the problem then, I know you would'nt accept it but the fact remains as is.

As you yourself has mentioned https://in.mathworks.com/matlabcentral/answers/479467-error-undefined-function-or-variable#comment_743665

If you're still not able to cope up with all the mentioned above suggestions , I request you to upload your script file here, so that I can rectify the mistakes if any.

[Walter Roberson]

You cannot define the same function twice in one script (except in some cases having to do with nested functions)

[Shikhar Sharma]

Please find attached.

[madhan ravi]

Really? Comeon, that's a pdf file not a script file attach your file with .m extension.

[Shikhar Sharma]

PFA.

[Walter Roberson]

All function definitions must be at the end of a script. No exceptions.

Possibly they intend that you use separate .m files for each section.

[madhan ravi]

Looks like you didn't give any attention to the suggestion , well done :). See the attached file.

Please again don't miss the valuable comment given by sir Walter

https://in.mathworks.com/matlabcentral/answers/479467-error-undefined-function-or-variable#comment_743680

[Shikhar Sharma]

Thank you very much for your time. I am quite new to this and trying to cope up with it.

Thank you for being patient. :)