How do I create two MATLAB for loops

Hi,

I am new to MATLAB and my loops don't work out the way I want them to.

I have a basic set of data (96 samples), for all the new added samples I want the loop to be performed. First I want to determine the slope of the new dataset. This for loop was working perfektly when performed with performed with p=1. Afterwards, with line3 + Max3, I want to find out the localmax for the different p's. Line3 is calculated perfectly with 1:2 instead of p, when replaced it doesn't work. The error is: Index in position 1 exceeds array bounds. Index must not exceed 1.

I want to get sRay1l/sRay1r for all p's and afterwards the Ray1left to be calculated with this value.

new_samples = Xstart.nSample - base_samples;        
for p = 1:new_samples                               
    for k = 1:Xstart.nEm                            %slope
        if (0 < k) && (k < Xstart.nEm)
            dx3(p,k) = (Xstart.X(p,k+1,66) - Xstart.X(p,k,66)) / 2; %Bei Ex=447 nm
        else
            dx3(p,k) = 0;
        end
    end
    line3 = Xstart.X(p,:,66); 
    Max3 = islocalmax(line3,2);
    if Max3(p,64) == 1
        sRay1l = 54+find(dx3(p,55:57)<0.01);                      %slopt left from localmax < 0.01 Abstand 
        if sRay1l > 0                                           %if there is sRay1l
            Ray1left(p) =  Xstart.Em(64) - Xstart.Em(max(sRay1l(p))); %lower boundary
        else                                                    %otherwise distance = 0
            Ray1left(p) = 0;
        end
        sRay1r = 64+find(dx3(p,65:71)>0);                         %slopt left from localmax > 0
        if sRay1r > 0
            Ray1right(p) = Xstart.Em(min(sRay1r(p))) - Xstart.Em(64); %above scatter
        else
            Ray1right(p) = 0;
        end
    else
        Ray1left(p) = 0;                                          
        Ray1right(p) = 0;
    end
end

Maybe someone is able to help.

Cheers,

Hanna

[Jan]

Please post the complete error message. Then the readers do not have to guess, in which line the error occurs.

This part looks strange:

for k = 1:Xstart.nEm                            %slope
    if (0 < k) && (k < Xstart.nEm)
        dx3(p,k) = (Xstart.X(p,k+1,66) - Xstart.X(p,k,66)) / 2; %Bei Ex=447 nm
    else
        dx3(p,k) = 0;
    end
end

In the loop over k=1:Xstart.nEM all k are > 0 and only the last k is not < Xstart.nEm. A simpler version:

dx3(p, Xstart.nEm) = 0;
dx3(p, 1:Xstart.nEm-1) = diff(Xstart.X(p, :, 66) / 2; %Bei Ex=447 nm

[Jeffrey Clark]

@Johanna Huber, you said line3 = Xstart.X(p,:,66) works when p=1:2 as would Max3 = islocalmax(line3,2) and following uses of it; in that case line3 is a matrix (1:2,:) and Max3 is a matrix. Now when p is a single value line3 and Max are only vectors (:) which will error out on statements like if Max3(p,64) == 1.