allow negative data log plots with OpenGL+FLTK graphics (bug #34232) * mx-inlines.cc (mx_inline_any_positive): New function. * lo-mappers.h (xpositive_sign (double), xpositive_sign (float)): New functions. * fNDArray.h, fNDArray.cc (FloatNDArray::any_element_is_positive): New function. * fMatrix.h, fMatrix.cc (FloatMatrix::any_element_is_positive): New function. * dNDArray.h, dNDArray.cc (NDArray::any_element_is_positive): New function. * dMatrix.h, dMatrix.cc (Matrix::any_element_is_positive): New function. * graphics.h.in (log_scaler::do_neg_scale): New function. (log_scaler::scale (const Matrix&) const, log_scaler::scale (const NDArray&) const): Call do_neg_scale if no array elements are positive. * graphics.cc (axes::properties::get_axis_limits): Omit zero from positive values for log plots. Correctly widen range for all negative log plots.

--- a/liboctave/fNDArray.cc	Wed Oct 26 07:44:55 2011 -0400
+++ b/liboctave/fNDArray.cc	Wed Oct 26 14:19:54 2011 -0400
@@ -514,6 +514,13 @@
 }
 
 bool
+FloatNDArray::any_element_is_positive (bool neg_zero) const
+{
+  return (neg_zero ? test_all (xpositive_sign)
+          : do_mx_check<float> (*this, mx_inline_any_positive));
+}
+
+bool
 FloatNDArray::any_element_is_nan (void) const
 {
   return do_mx_check<float> (*this, mx_inline_any_nan);