Calculating the RMS (Root-Mean-Square) Average

Hi all. So I'm trying to calculate the rms average. The image below shows the exact question

. The answer I get after running my script is 2.5. However, when I calculate this by hand I get 6.20. Either way, one of them is wrong. Any help checking my code is greatly appreciated!

N=input('Input the number of data points:');

for ii=1:N

      A=input('Enter the value of x: '); % A is the variable to read in user input
      x_rms=sqrt(1/N.*(sum(x(ii).^2)));
  end

fprintf('The root-mean-square value is:%d\n',x_rms)

[CHETARIYA SUNIL]

hello I'm tring but geting propted by this:

rms_voltage

Input the number of data points:

4

Enter the value of x:

1:0.5:2

Unrecognized function or variable 'x'.

Error in rms_voltage (line 6)

x_rms=sqrt(1/N.*(sum(x(ii).^2)));

Answer 1

[Star Strider]

You’re almost there. Collect the numbers in the loop, then do the calculation after the loop:

N=inputdlg('Input the number of data points:');  N = str2num(N{:});
for ii=1:N
    A=inputdlg('Enter the value of x: '); A = str2num(A{:});% A is the variable to read in user input
    x(ii) = A;
end
x_rms=sqrt(1/N.*(sum(x.^2)));
fprintf('The root-mean-square value is: %f\n',x_rms)

I used the inputdlg function because I prefer it. You can substitute your input calls.

[Matthew Lintern]

Brilliant, thanks so much! Also, thanks for the introduction to the inputdlg function!

[Star Strider]

My pleasure!

I prefer inputdlg because it doesn’t mess up the Command Window, even if requires an extra line or two of code.

[idris]

We venerate loyalty to the developers of MATLAB as the tool "inputdlg" is okay.

[Star Strider]

@idris— What?