Error with quiverm function

I have the following code that returns me contour plots of phi, Q and quiver plots of u,v on a map. The first section just fiddles around with the data so its the write magnitude and shape.

However when I use the quiverm function it returns me this error:

 ??? Error using ==> quiverm
 Inconsistent dimensions for inputs

 Error in ==> model at 54
 quiverm(lat,lon,u,v)

phi, Q, u and v are all 21*41 arrays. Longitude and latitude (lon and lat) are length 41 and 21 respectively.

Can anyone tell me why I'm getting this error?

 close all
 clear all

 load 'Q.ascii'
 load 'u.ascii'
 load 'v.ascii'
 load 'phi.ascii'

 m = 43;
 n = 21;

 Q = reshape(Q,n,41);
 u1 = reshape(u,n,m);
 v1 = reshape(v,n,m);
 phi1 = reshape(phi,n,m);

 Q = flipud(Q);
 u2 = flipud(u1);
 v2 = flipud(v1);
 phi2 = flipud(phi1);

 u3 = u2/100;
 v3 = v2/100;
 phi3 = phi2/100;

 u = u3(:,2:42);
 v = v3(:,2:42);
 phi = phi3(:,2:42);

 lat = zeros(1,21);
 lon = zeros(1,41);

 for n = 1:21
 lat(n) = -40.5 + 4.5*(n-1);
 end

 for m = 1:41
 lon(m) = (9*(m-1));
 end

 figure(4)
 axesm('eqdcylin', 'maplonlimit', [0 360], 'maplatlimit' , [-40.5 40.5], 'frame', 'on', 'grid', 'on');
 geoshow('landareas.shp', 'facecolor', 'none');
 contourfm(lat,lon,phi);

 figure(5)
 axesm('eqdcylin', 'maplonlimit', [0 360], 'maplatlimit' , [-40.5 40.5], 'frame', 'on', 'grid', 'on');
 geoshow('landareas.shp', 'facecolor', 'none');
 contourm(lat,lon,Q);

 figure(1)
 axesm('eqdcylin', 'maplonlimit', [0 360], 'maplatlimit' , [-40.5 40.5], 'frame', 'on', 'grid', 'on');
 geoshow('landareas.shp', 'facecolor', 'none');
 quiverm(lat,lon,u,v)

Answer 1

[Rob Comer]

Unlike quiver, quiverm does not automatically expand its first two inputs if they are vectors and the third and fourth inputs are matrices, even if their lengths are consistent with size of the two matrices. You need to precede the call to quiverm with a call to meshgrat.

I see no need for this inconsistency; I think that what you tried should work and that quiverm should be fixed to support it. Thanks for pointing out the issue.

Answer 2

[Chad Greene]

Matlab's quiverm function mixes up u and v. It also scales the vectors in a strange way. Andrew Roberts' ncquiverref fixes the problems, as does quivermc.