Re: Different specification of parameters; octave and gnuplot

[Ben Abbott]

On Aug 22, 2010, at 8:03 AM, pathematica wrote:

> I have no problem, this is not urgent and nothing bad will happen if no one
> replies!
> 
> I am merely interested to know something. It is possible that my confusion
> is based on missing a key bit of explanation in the manual.
> 
> So ... using gnuplot for 3d plots from octave
> 
> I note that when specifying a particular view for a 3d plot (for example to
> align the visual axis with the line through the origin with the homogeneous
> coordinate on the projective plane P2 [k : k : k] to generate radial
> symmetry of order three), it is possible to send parameters for azimuth and
> elevation as a 1x2 vector using view().
> 
> As I am sure you will all know, gnuplot reports the elevation and azimuth on
> the plot. The parameters are reported in that particular order, whereas
> octave requires the parameters to be specified in the opposite order, ie
> azimuth then elevation. Also, the octave requires the elevation to be
> specified as a negative offset from 90 degrees compared with the elevation
> reported in gnuplot. 
> 
> Have I understood this correctly and, if so, is there an interesting
> explanation for the different convention (or, perhaps more accurately, the
> lack of convention)? Also, is there a reason why the parameters are
> specified in degrees rather than radians?
> 
> As noted at the beginning - this is merely of interest and it is not urgent. 
> 
> Thank you so much for octave. (Seriously, thank you; - compliments like this
> will always be a form of litotes and they can never do it justice!).

The developers of Octave and Gnuplot have some degree of cooperation. However, 
as Octave has chosen to favor compatibility with Matlab there will necessarily 
be differences in conventions between Octave and Gnuplot.

Thus, regarding the convention for specifying the axes view property, Octave 
has adopted the approach used by Matlab, which is different from that of 
Gnuplot.

Ben