Index exceeds matrix dimensions is the error I'm getting.

The error is showing in the Tair_monthly loop. How can I fix this error to display the data?

    clear
    clc
    %Load treering data only file. SiteNo. specises column removed
    loc=xlsread('Tree_Ring_Data_AK.xlsx');
    year=loc(:,4); % RWI-year change to fit your sheet format
    lat=loc(:,2);%latitude
    lon=loc(:,1);%longitude
    %Function that translate lat and lon into coordination counts
    [lonf,latf]=TransLatLon(lon,lat);

    files=dir('*.nc');%load Temperature files
    for y=1:length(files);%Number of years in your climate file
        temp=ncread(files(y).name,'Tair_monthly'); % variable name in climate file
        ind=find(year==y+1900);
        lont=lonf(ind);
        latt=latf(ind);
        %
        for i=1:length(latt);
            for j=1:12;
                Tair_monthly(ind(i),j)=temp(lont(i),latt(i),j);
            end
        end      
    end  
    ind=find(year<1901);
    for j=1:12
        Tair_monthly(ind,j)=NaN;
    end

Answer 1

[Aquatris]

The reason is simple; since year and Tair_monthly variable do not have sam number of elements, the ind variable tries to access rows of Tair_monthly that do not exist.

Your "year" variable is your raw data. Then you create a variable that has less elements compared to "year" variable called "latt". Then you create the rows of your "Tair_monthly" variable using the reduced number. However at the end you try to reach the indeces that are coming from the "year" variable, which do not exist in the "Tair_monthly" variable.

[Ayo Deas]

Ok. Thank you for the explanation. Do you have a suggestion on how to adjust my code so I can display the data?

[Aquatris]

Depends on what you are trying to do with your code.

Easiest way is replace;

ind=find(year<1901);
for j=1:12
      Tair_monthly(ind,j)=NaN;
end

with;

ind=find(year<1901);
for j=1:12
      Tair_monthly(ind(ind<length(Tair_monthly)),j)=NaN;
end

[Ayo Deas]

Thank you for the suggestion. I adjusted the line for my last loop however I'm still getting the same error for the nested loop which in this case is line 19. The nested loop should produce an array with 12 columns. Any suggestions on how to adjust this loop?

[Aquatris]

You need to provide your data for me to further help.

But one thing you can check is if your "temp" variable is a 2D or 3D matrix. I do not have the data so I cannot determine the actual cause.

The reason for the error is basically your variable has 5 elements and you are trying to reach 6. Just use debug tool, stop the program at the error, check what these values are (lont(i),latt(i),j), check the size of your temp etc. and from there you can determine the cause.