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/lo-mappers.h	Wed Oct 26 07:44:55 2011 -0400
+++ b/liboctave/lo-mappers.h	Wed Oct 26 14:19:54 2011 -0400
@@ -218,6 +218,10 @@
 extern OCTAVE_API bool xnegative_sign (double x);
 extern OCTAVE_API bool xnegative_sign (float x);
 
+// Test for positive sign.
+inline bool xpositive_sign (double x) { return ! xnegative_sign (x); }
+inline bool xpositive_sign (float x) { return ! xnegative_sign (x); }
+
 // Some old rounding functions.
 
 extern OCTAVE_API octave_idx_type NINTbig (double x);