How to make NxN matrix from excel dataset

Hi there,

I got excel dataset which has longitude(1xn)), latitude(1xn) and elevation(1xn) as described in the attached file.

How can I convert elevation dataset into NxN matrix?

Note: Data points are randomly distributed. not in exact order as described in the example.

Answer 1

[Walter Roberson]

griddata()

[Ravindu Lokuliyana]

Hi Walter,

Thank you for your answer. Can you please help me out with an example?

[Walter Roberson]

data = xlsread('matlab_example.xslx');
N = size(data, 1);
Long = data(:, 1);
Lat = data(:,2);
Minlong = min(Long) ;
Maxlong = max(Long) ;
Longvec = linspace(Minlong, Maxlong, N) ;

Minlat = min(Lat) ;
Maxlat = max(Lat) ;
Latvec = linspace(Minlat, Maxlat, N) ;

Elev = data(:, 3);

Out = griddata(Long, Lat, Elev, Longvec(:), Latvec(:).');

[Ravindu Lokuliyana]

Thank you very much. It works well for me.

But I got large excel data values (more than 300,000) in my file. In that case it's somewhat hard to execute.

If you have further suggestions, I would greatly appreciate.

[Walter Roberson]

Set N to a smaller value, probably not more than about 1500 or so.