How to make a color-map from lat long and data.

I have an excel file which has 3 coloumns longitude,latitude and data.I want to make a colormap.How can I do that.I am attaching the data file and a picture which shows what I want to do.

[Ameer Hamza]

Is the data in excel file only corresponds to colormap or the background image too?

Answer 1

[Ameer Hamza]

try this

data = readmatrix('data.xlsx');

lat = data(:,1);
lon = data(:,2);
val = data(:,3);

latV = linspace(min(lat), max(lat), 100);
lonV = linspace(min(lon), max(lon), 100);
[latG, lonG] = meshgrid(latV, lonV);
valG = griddata(lat, lon, val, latG, lonG);

contourf(latG, lonG, valG, 100, 'LineColor', 'none')
colormap(jet)
colorbar

[TAPAS]

I have a .grd file which contains the elevation data for the same region as above. Can I plot the data as background??

[Ameer Hamza]

Can you share the file?

[Ameer Hamza]

You can try to plot it over the .grd file by using hold on.

[Ameer Hamza]

You can use this package to read .grd file: https://www.mathworks.com/matlabcentral/fileexchange/25683-grdread2 and read the discussion here to see how to plot it: https://www.mathworks.com/matlabcentral/answers/446756-plot-grd-file.