Slatec's polyfit is giving absolutely crazy answers.
perldl> $x = xvals(50) perldl> $y = 15.2 + $x*3.14 + $x*$x/3.14 + ($x*$x*$x); # some random cubic perldl> use PDL::Slatec; perldl> ($ndeg,$r,$ierr,$a) = polyfit($x,$y,ones($x),pdl(4), $eps=zeroes($x)); perldl> p $ndeg [4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4] perldl> help $r This variable is Double D [50,50] The output variable $r should contain either the polynomial coefficients (makes most sense), and hence be something like [5,50], or the actual fitted values of the polynomial (seems to agree most with the documentation) and hence be just [50] -- [50,50] is crazy. Has anyone actually tried to use polfit() or polyfit() lately? _______________________________________________ Perldl mailing list [email protected] http://mailman.jach.hawaii.edu/mailman/listinfo/perldl
