// In this example, we use Inquire to determine if an input data field is
// scalar or vector. If it's vector, we extract the x component for 
// visualization using Isosurface. Otherwise, we use the original data field.

macro contour(data)
{
   scalar = Inquire(data,"is scalar");
   output = Compute("$0 ? $1 : [$1.x]", scalar, data);
   contours = Isosurface(output, number = 3);
   camera = AutoCamera(contours);

   switchnumber = scalar+1;

   caption1 = Caption("vector field");
   caption2 = Caption("scalar field");
   caption = Switch(switchnumber, caption1, caption2);
   
   collected = Collect(caption, contours);
   Display(collected,camera);
}

scalarfield = Import("watermolecule");
vectorfield = Gradient(scalarfield);
scalarslice = MapToPlane(scalarfield);
vectorslice = MapToPlane(vectorfield);

contour(scalarslice);
contour(vectorslice);