How to colour contour temperature data over its lat and lon?

Hi hope all is well,

I have a set of field measurements of temperuature, and the lat lon and depth of where the observation was made. I am trying to plot these data onto a map with temperature in colour contour, at its lat lon it was taken.

My collection contains a mighty 45,000 ish rows thus elimated a few approaches such as mesh, my variables are : lat , lon , temp . I also used geoshow for background map, thus I believe would also be a limiting factor of code choices.

So far, I have tried to use the contour function but I kept getting an error of Z must be at least 2 by 2 , (however, my Z , temp is a single column array).

Please let me know how to plot my temp contours, thanks in advance

Answer 1

[KSSV]

Let lon,lat,Z be your data

M = 100 ; N = 100 ; 
xi = linspace(min(lon),max(lon),M) ;
yi = linspace(min(lat),max(lat),N) ;
[Xi,Yi] = meshgrid(Xi,yi) ;
F = scatteredInterpolant(lon,lat,Z,'nearest','none') ;
Zi = F(Xi,Yi) ;
contourf(Xi,Yi,Zi)

[P3tra_]

Thank you KSSV for your help,

However, it does not agree with my fan shape base map too well as it gives an retanguler framed output.

I tried to follow the attached example (openExample('map/DisplayWorldMapWithColormapWithCustomStepSizeExample'), yet, the variable they used is a n by m matrix whilst my variable is an n by 1 array of one column.

I wonder if you could please let me know how to apply the contourm function with n by 1 shape of Z?

[KSSV]

Why dont you attach your data?

[P3tra_]

here you go KSSV

Answer 2

[P3tra_]

Thanks to @KSSV's kind direction, I have successfully got me contour over me geoshow map. However, they do not agree with each other. I reckon it is the lack of projection on my contours, but I do not know for sure. Code as below (my variables are lat , lon , temp):

%2D 'Contour over map'

M = 100 ; N = 100 ; 
loni = linspace(min(lon),max(lon), M )
lati = linspace(min(lat),max(lat), N )
[LONi,LATi] = meshgrid(loni,lati)
plot = scatteredInterpolant(lon,lat,temp,'nearest','nearest')
Zi = F (LONi,LATi)


figure

hold on

worldmap ([60 85],[-130 -45])
title ('filetitle')
geoshow('landareas.shp','FaceColor',[0.7 0.8 0.6]) 

contourm(LATi,LONi,Zi,'ShowText')

hold off

Thanks in advance