[Octave-bug-tracker] [bug #45125] griddata matlab incompatibility

[Rik]

Follow-up Comment #1, bug #45125 (project octave):

Could you try the following in Matlab?


x=rand(10,1);
y=rand(10,1);
z=rand(10,1);
xi=rand(5,1);
yi=rand(5,1);
[xi2, yi2, zi2] = griddata(x,y,z,xi,yi)


What I find in Octave is that zi2 is a 1-D vector, not a 2-D matrix.  When you
try to call surf with 


surf (xi2, yi2, zi2)


you get an error because zi2 needs to be a 2-D matrix (surface).

>From the documentation, it seems that if xi and yi are vectors then the output
should also be a vector of zi at the requested points.  In that case, perhaps
plot3() should be called instead of mesh() to plot individual points.

The code in griddata.m is


if (nargout == 3)
  rx = xi;
  ry = yi;
  rz = zi;
elseif (nargout == 1)
  rx = zi;
elseif (nargout == 0)
  mesh (xi, yi, zi);
endif


which could be modified to


elseif (nargout == 0)
  if (isvector (zi))
    plot3 (xi, yi, zi);
  else
    mesh (xi, yi, zi);
  endif
endif




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