How to pass variables from a matlab file to function in another file

I have made a Matlab file SystemDetail.m where I have taken some data as input from the user. I have taken two matrices n, d and a constant o as input from the user in SystemDetail.m. I have another matlab function file GenAlgo.m. I want to use the value of n, d and o as an argument of a function in this function file GenAlgo.m. How should I do it? I have written function sysr = SystemDetail(n,d,o) in my file GenAlgo.m where n d and o are taken from user in SystemDetail.m I am getting the error ' Not enough input arguments. Please tell Where am I wrong?

[Stephen23]

You need to do these tutorials:

https://www.mathworks.com/help/matlab/getting-started-with-matlab.html

And then read these:

https://www.mathworks.com/help/matlab/ref/function.html

https://www.mathworks.com/help/matlab/matlab_prog/share-data-between-workspaces.html

and then simply pass the values as input/output arguments.

Answer 1

[Image Analyst]

You could pass the values into the other function as input arguments, or you could pass in just the filename and let the other function read in the mat file itself. Or, if it's a constant, known filename, you wouldn't even have to pass in the filename, it will just know what it is because you hard coded it in.

[Rakesh Jain]

So in this case, is he following command correct: function sysr = SystemDetail(n,d,o)

[Rakesh Jain]

I have written

function sysr = SystemDetail(n,d,o)

in my file GenAlgo.m, where n d and o are taken from user in SystemDetail.m I am getting the error

'Not enough input arguments.'

Where am I wrong?

[Image Analyst]

Show the complete error message (ALL the red text) , or attach the code because otherwise I don't know how you're calling SystemDetail() from within GenAlgo.m. According to the error message, you're calling it but not passing any arguments to it. It's fine if SystemDetail is defined in GenAlgo.m but you need to pass arguments to it when you call it because you defined it to require inputs.

[Rakesh Jain]

SystemDetail.m
function SystemDetail(n,d,order)
n = input('Enter the numerator coefficient from highest power to the lowest in square brackets')
d = input('Enter the denominator coefficient from highest power to the lowest in square brackets')
order = input('Enter the order of the system into which you wish your system be reduced to')
g = tf(n,d)
bode(g)
figure
step(g)

GenAlgo.m
function sysr = SystemDetail(n,d,o)

[Image Analyst]

You can't define SystemDetail in both m-files. It's defined in SystemDetail.s do do not define it again in GenAlgo.m. You need to CALL it in GenAlgo.m. So don't have the function keyword before systr. Also, as we can see from SystemDetail.m, SystemDetail() does not even return a value so you can't take the resul and put it into sysr. Finally, SystemDetail does not use the values of n, d, and order that you pass it - it immediately overwrites them with the results of input(). So either put the input lines in GenAlgo.m, or delete the input arguments.

Suggested fix:

SystemDetail.m
function SystemDetail(n,d,order)
g = tf(n,d)
bode(g)
figure
step(g)
% etc. -- other stuff with order or whatever...

GenAlgo.m
n = input('Enter the numerator coefficient from highest power to the lowest in square brackets')
d = input('Enter the denominator coefficient from highest power to the lowest in square brackets')
order = input('Enter the order of the system into which you wish your system be reduced to')
% Call SystemDetail()
SystemDetail(n,d,order);

[Rakesh Jain]

Got it. Thanks