Matrix and array indices

Hi all,

I try ti run a loop as described below. However I keep having the same error and I dont understand where it comes from (see below).

Can someone help please?

Index in position 1 is invalid. Array indices must be positive integers or logical values.

Error in read_NC_create_data (line 37) M(i,1) = M(i,1) + u10(j,k,i+delaytime);

close all
clear all
clc

cd ('D:\SEEC\Matt\');

% Era5 folder:
filename = 'june_wind.nc';

% Files in the folder:
ncTime = ncread(filename,'time');
ncLon = ncread(filename,'longitude');
ncLat = ncread(filename,'latitude');
u10 = ncread(filename,'u10');
v10 = ncread(filename,'v10');

% date number into date calendar:
ncDate = datetime(1900,1,1,'Format','dd/MM/yyyy HH:mm:ss') + hours(ncTime);

% n rows according to the number of timesteps from drifter data; 
% m columns for data to extract
M = zeros(566,2); 

N = xlsread('REEF_for_Matt.xlsx'); % Matrix to compare and select correct data.
N_Lon = N (:,3);
N_Lat = N(:,4);

% n-1 Start of periof of interest:
delaytime = 130;

for i = 1:566 % length number timestep drifter
    clear j k
    
    j = N_Lon(i,1);
    k = N_Lat(i,1);
    
    M(i,1) = M(i,1) + u10(j,k,i+delaytime);
    
end

Answer 1

[Matt J]

Presumably your N_Lon and N_Lat values are not positive integers.

[Jonathan Demmer]

I checked yesterday and yes it was the problem... thank you for the answer.

[Matt J]

you're welcome, but please Accept-click the answer to indicate that your problem is resolved.