Make a grid (1 x1) out of scattered insitu data and take the average of each grid that has data

Hello,

Please, I am working on some insitu scattered dataset, I want to make the data into a grid, and then average all the data within that grid, such as the image below were I have latitude, longitude and a third variable (temperature). I want to grid it into 1 x 1 resolution.

Latitude = 22 - 25

Longitude = 113 - 118

Please what is the best way to do this? Thanks in advance.

Answer 1

[Mathieu NOE]

hello

this would be my suggestion, based on dummy data (left picture) - result appears in right picture

clc
clearvars

% dummy data
n = 50;
x = linspace(112,120,n)+0.25*rand(1,n); % Longitude 
y = linspace(22,24,n)+0.5*rand(1,n); % Latitude
z = 10+y; % temperature

figure(1),
scatter(x,y,z,z,'filled');
colormap('jet');
colorbar('vert');

%% main code
% grid spacing and min / max values for display
dx = 1;
dy = 1;
xmin = 113;
xmax = 118;
ymin = 22;
ymax = 25;


x2 = xmin:dx:xmax;
y2 = ymin:dy:ymax;
xc = x2(1:end-1)+0.5*dx;
yc = y2(1:end-1)+0.5*dy;

figure(2),hold on

for ci = 1:numel(x2)-1
    ind1 = find((x>=x2(ci)) &  (x<=x2(ci+1)));
    y_selected = y(ind1);
    z_selected = z(ind1);
    
    for ck = 1:numel(y2)-1
        ind2 = find((y_selected>=y2(ck)) &  (y_selected<=y2(ck+1)));
        z_mean(ck,ci) = mean(z_selected(ind2));   
        scatter(xc(ci),yc(ck),150,z_mean(ck,ci),'filled');
    end
end
    
colormap('jet');colorbar('vert');
xlim([xmin xmax]);
ylim([ymin ymax]);
xticks(x2);
yticks(y2);
view(2);
hold off

Answer 2

[CHARLES ADDEY]

Thanks alot @Mathieu NOE, this really does what i need

[Mathieu NOE]

My pleasure !