Matlab coneplot meshgrid error MATLAB:griddedInterpolant:NdgridNotMeshgrid3DErrId / not plotting anythin

Question

Basically I want to plot a 3D vector field using coneplot in Matlab. My script looks like this:

data=oommf2matlab('420x350x5-2_5-5.omf');
x=linspace(data.xmin,data.xmax,data.xnodes);
y=linspace(data.ymin,data.ymax,data.ynodes);
z=linspace(data.zmin,data.zmax,data.znodes);
[X,Y,Z]=meshgrid(y,x,z);
scale=4;
angle = data.datay ./ data.datax;
colors = angle;
figure;
coneplot(data.positionx,data.positiony,data.positionz,data.datax,data.datay,data.dataz,X,Y,Z,scale,colors);

oommf2matlab is a function for converting my data into matlab and returns a structure like this:

xmin: 0
ymin: 0
zmin: 0
xmax: 4.2400e-07
ymax: 3.5400e-07
zmax: 1.2500e-08
xnodes: 212
ynodes: 177
znodes: 5
datax: [212x177x5 double]
datay: [212x177x5 double]
dataz: [212x177x5 double]
positionx: [212x177x5 double]
positiony: [212x177x5 double]
positionz: [212x177x5 double]

Running this script gives me an error

Error using interp3 (line 146) Input grid is not a valid MESHGRID.

Error in coneplot (line 144) ui = interp3(x,y,z,u,cx,cy,cz,method);

Error in omf2cone (line 11) coneplot(data.positionx,data.positiony,data.positionz,data.datax,data.datay,data.dataz,X,Y,Z,scale,colors);

If traced the error via debugging to the MATLAB:griddedInterpolant:NdgridNotMeshgrid3DErrId error which looks like this:

identifier: 
'MATLAB:griddedInterpolant:NdgridNotMeshgrid3DErrId'

message: 
Data is in MESHGRID format, NDGRID format is required.
Convert your data as follows:
P = [2 1 3];
X = permute(X, P);
Y = permute(Y, P);
Z = permute(Z, P);
V = permute(V, P);
F = griddedInterpolant(X,Y,Z,V)
cause: {0x1 cell}
stack: [3x1 struct]

This is strange to me, because interp3 already does what the error suggests as a fix.

Also if I let coneplot generate the mesh itself via:

coneplot(data.datax,data.datay,data.dataz,X,Y,Z,scale,colors);

There is no error, however there is no plot created whatsoever, only the axis of the figure.

Answer 1

instead of using meshgrid use griddedInterpolant() instead so that your data is in the format identified in the error.

Also part of your error could be in this line [X,Y,Z]=meshgrid(y,x,z); where instead you want [X,Y,Z]=meshgrid(x,y,z); ? This could cause the syntax error you are describing