// Test Poly2D_interp
System.out.println("Testing Poly2D_interp");
Poly2D_interp z = new Poly2D_interp(x1,x2,y,3,3);
localflag = abs(z.interp(2.5,2.5)-5.0) > sbeps;
globalflag = globalflag || localflag;
if (localflag) {
fail("*** Poly2D_interp: Inaccurate 2D polynomial interpolation.");
}