Error Message during execution

My Code is;

Ave3ON = zeros(size(S));
Ave5ON = zeros(size(S));
Ave7ON = zeros(size(S));
AvethdON = zeros(size(S));
Ave3OFF = zeros(size(S));
Ave5OFF = zeros(size(S));
Ave7OFF = zeros(size(S));
AvethdOFF = zeros(size(S));

for i=1:length(S)
    M3=([S(i).HV3]);
    M5=([S(i).HV5]);
    M7=([S(i).HV7]);
    Mthd = ([S(i).thd]);

    Ave3ON(i)=mean(M3(90000-S(i).date*1667:90000));
    Ave5ON(i)=mean(M5(90000-S(i).date*1667:90000));
    Ave7ON(i)=mean(M7(90000-S(i).date*1667:90000));
    AvethdON(i)=mean(Mthd(90000-S(i).date*1667:90000));
    Ave3OFF(i)=mean(M3(110000:110000+S(i).date*1667));
    Ave5OFF(i)=mean(M5(110000:110000+S(i).date*1667));
    Ave7OFF(i)=mean(M7(110000:110000+S(i).date*1667));
    AvethdOFF(i)=mean(thd(110000:110000+S(i).date*1667));
end

Error Message is;

Error using computeperiodogram>validateinputs (line 196)

The input must be either a vector or two-dimensional matrix.

Error in computeperiodogram (line 61)

[x1,~,y,is2sig,win1] = validateinputs(x,win,nfft);

Error in periodogram (line 215)

[Sxx,w2,RSxx,wc] =

computeperiodogram(x,win,nfft,esttype,Fs,options);

Error in thd>timeTHD (line 126)

[Pxx, F] = periodogram(x,w,n,fs,'psd');

Error in thd (line 89)

[r, harmPow, harmFreq] = timeTHD(plotType, harmType,

varargin{:});

Error in Untitled2 (line 28)

AvethdOFF(i)=mean(thd(110000:110000+S(i).date*1667));

Struct S =

480×1 struct array with fields:

name

date

HV3

HV5

HV7

thd

[FG]

Thank you per isakson

Answer 1

[Walter Roberson]

    Ave3ON(i)=mean(M3(90000-S(i).date*1667:90000));
    Ave5ON(i)=mean(M5(90000-S(i).date*1667:90000));
    Ave7ON(i)=mean(M7(90000-S(i).date*1667:90000));
    AvethdON(i)=mean(Mthd(90000-S(i).date*1667:90000));

Okay, parallel indices into 4 different arrays. Makes sense.

    Ave3OFF(i)=mean(M3(110000:110000+S(i).date*1667));
    Ave5OFF(i)=mean(M5(110000:110000+S(i).date*1667));
    Ave7OFF(i)=mean(M7(110000:110000+S(i).date*1667));

Okay, parallel indices into 3 of the 4 different arrays from above. That's odd, I wonder why the 4th array isn't being used?

    AvethdOFF(i)=mean(thd(110000:110000+S(i).date*1667))

The destination location parallels the block of 4 above, and the code structure parallels the three lines above it, but why have you suddenly switched from indexing an array named Mthd, to instead requesting the calculation of Total Harmonic Distortion (thd) ?

[FG]

Thank you Walter.. It wad just a mistyping and it's solved : )