plotting rainfall data, having latitude and longitude, on map

Hi, I have problem with plotting rainfall data (with latitude and longitude) on map. I googled it, there were many answers but couldn't do it. My data has latitude(1x86400),longitude(1x86400) and corresponding rainfall (1x86400). I have to plot rainfall data on map corresponding to latitude and longitude. My code is similar to below one but not working though not showing any error. Need help.Thank you.

A=importdata('new.dat');
lat=A(:,1);
lon=A(:,2);
lat1=meshgrid(lat,1:25);
lon1=meshgrid(lon,1:25);
z=A(:,3);
z1=meshgrid(z,1:25);
worldmap('world')      % initializes map
contourm(lat1,lon1,z1)    % plots contours
c = load('coast.mat'); % loads coastlines
plotm(c.lat,c.long)    % plots coastlines

[the cyclist]

Can you be more specific about what is not working?

Is it possible for you to upload your file new.dat, or MAT file with the data, so that people can run your code? (I won't be able to, since I do not have the Mapping Toolbox.)

[Madan Kumar]

I have attached new.txt file since new.dat file was not supported. When I am running the program there is no error but the data are not plotted on map.

Answer 1

[KSSV]

Your data is a scattered data.....you cannot use meshgrid as the way you have used. You need to interpolate the data into a grid and then plot. Check the below code:

A=importdata('new.dat');
lat=A(:,1);
lon=A(:,2);
z=A(:,3);
lon0 = min(lon) ; lon1 = max(lon) ;
lat0 = min(lat) ; lat1 = max(lat) ;
N = 100 ;
x = linspace(lon0,lon1,N) ;
y = linspace(lon1,lat1,N) ;
[X,Y] = meshgrid(x,y) ;

F = scatteredInterpolant(lon,lat,z) ;
Z = F(X,Y) ;

worldmap('world')      % initializes map
contourm(X,Y,Z)    % plots contours
c = load('coast.mat'); % loads coastlines
plotm(c.lat,c.long)    % plots coastlines

[Madan Kumar]

Thank you so much. It plots world map and data over it. But I need to plot only the region required for me and data over it. I tried using worldmap([-50 50],[160 -30]). Although it is showing the required map but not plotting data over it. Need help.

[Arnob Das]

thank you