how to solve the error comes in line 25

clear, clc

format longg

GM = 0.3986004415E+15;

alpha = 0.63781363E+07;

% Load data

%data = importdata('EGM08.txt');

data = readtable('EGM08.txt', 'ReadVariableNames', false);

% Extract sigma and beta values

sigma = data(:,5);

beta = data(:,6);

% Initialize Dw

Dw = 0;

% Calculate Dw using the equation

for n = 0:78

summation = 0;

for m = 0:2190

summation = summation + (sigma(m+1)^2 + beta(m+1)^2); % This is the line 25

end

Dw = Dw + sqrt((GM/alpha)^2 * summation);

end

% Display the result

disp(['Dw = ',num2str(Dw)]);

when running the program the following error comes.

Error using egm2008 (line 25)

Subscripting into a table using one

subscript (as in t(i)) is not

supported. Specify a row subscript and

a variable subscript, as in

t(rows,vars). To select variables, use

t(:,i) or for one variable t.(i). To

select rows, use t(i,:).

EGM08.txt have 2401334 rows and 6 columns.

Answer 1

[Voss]

These lines make sigma and beta tables with one variable each

sigma = data(:,5);
beta = data(:,6);

which produces the error when you try to index them with one subscript, as in sigma(m+1), later on.

Instead, make sigma and beta column vectors (presumably of a numeric type):

sigma = data.(5); 
beta = data.(6);  

https://www.mathworks.com/help/matlab/matlab_prog/access-data-in-a-table.html

[Prabhath Manuranga]

Thanks for your support Mr. Voss

[Voss]

You're welcome!