Hi,

I have a triangular domain,

tri2 = Triangle[{{-1/2, 0}, {1/2, 0}, {0, Sqrt[3]/2}}];

over which I've used NDSolve on a PDE. This gives me an interpolating function nudifference[x,y]. It seems to be working:

In[56]:= nudifference[0, .3]

Out[56]= -14.7

I'd like to find the maximum value of this interpolating function, nudifference, on my triangular domain, tri2. I tried it this way:

In[57]:= FindMaxValue[{nudifference[x, y], {x, y} \[Element] 
   tri2}, {x, y}]

During evaluation of In[57]:= InterpolatingFunction::dmval: Input value {1.,1.} lies outside the range of data in the interpolating function. Extrapolation will be used. >>

During evaluation of In[57]:= InterpolatingFunction::dmval: Input value {1.,1.} lies outside the range of data in the interpolating function. Extrapolation will be used. >>

During evaluation of In[57]:= InterpolatingFunction::dmval: Input value {1.,1.} lies outside the range of data in the interpolating function. Extrapolation will be used. >>

During evaluation of In[57]:= General::stop: Further output of InterpolatingFunction::dmval will be suppressed during this calculation. >>

Out[57]= -4.42683*10^-8

What am I doing wrong to get these errors?

Thanks,

Bentley