How can I fix this error?

[Khalid Mahmood]

Your question is not clear. What is i?

[Khalid Mahmood]

%Supposed this
function y=Question5(x,i)
..... 
end
Let, x=randi([-10 10],5,3)
y=Question5(x,3) 

[Hazal Yuvgun]

i is row

[Hazal Yuvgun]

I want to extract the first row from others

Answer 1

[Khalid Mahmood]

function y=Question5(x)

y=[];

rows=size(x,1);

y(1,:)=x(1,:);

for i=2:rows

y(i,:)=x(i,:)-x(1,:);

end

end

[Hazal Yuvgun]

Output is not correct. Output only shows the last row

[Khalid Mahmood]

in for loop y(i) ensures all rows. Like y(i,:)=x(i,:)-x(1,:); This is working now

[Hazal Yuvgun]

Thank you so much

Answer 2

[Steven Lord]

Where in your code do you define a variable named i? If the answer is some form of "nowhere" or "I don't" then MATLAB will call the built-in function to determine the value that should be used. That built-in function returns neither a positive integer value nor a logical value.

Answer 3

[Khalid Mahmood]

function y=Question5(x,i)
  y=[];
  if i==1
      y=x(1,:);
  else
      y=x(i,:)-x(1,:);
  end
end

[Khalid Mahmood]

save above code as Question5.m file. Then

>>x=randi([-10 10],5,3); % define x, or whatever x you want

>>y=Question5(x,1)

>>y=Question5(x,2)

>>y=Question5(x,3)

But I think you may need following code for advanced logic.