the 'polyarea' function dose not work well. how to solve it?

I want to calculate area of four polyshapes.

the result from one polygon seems wrong.(VFR_lon_merged, VFR_lat_merged) It returns NaN value.

I attacehd the data.

Please Let me know how to solve it.

Answer 1

[dpb]

>> VFR=[VFR_lat_merged VFR_lon_merged];
>> find(any(~isfinite(VFR),2))
ans =
   102
>> VFR(ans-5:ans+5,:)
ans =
   37.5443  126.4193
   37.5451  126.4259
   37.5456  126.4325
   37.5458  126.4392
   37.5458  126.4392
       NaN       NaN
   37.4425  126.4427
   37.4423  126.4432
   37.4421  126.4434
   37.4412  126.4442
   37.4402  126.4451
>> 

Your original data contains a NaN entry -- looks as though this could probably just be ignored, but I didn't try to see what the shape actually is nor where/how this might fit (or not) into the contour.

[Walter Roberson]

nan inside of a poly shape might possibly indicate multiple independent poly shapes together in one array.

[dpb]

Good point, Walter...didn't think about that even though the variable names indicate a good possibility...