[SciPy-user] Failed to plot array using gnuplot-py

iCy-fLaME icy.flame.gm at gmail.com
Wed Feb 1 14:23:38 CST 2006


On 2/1/06, Travis Oliphant <oliphant at ee.byu.edu> wrote:
> iCy-fLaME wrote:
>
> >On 2/1/06, Robert Kern <robert.kern at gmail.com> wrote:
> >
> >
> >>iCy-fLaME wrote:
> >>
> >>
> >>>Not sure what is going on, dont even know if this is a glitch cause by
> >>>gnuplot-py or scipy or python itself, but here is what i found out on
> >>>my system.
> >>>
> >>>Fedora Core 4
> >>>gnuplot-4.0.0-7
> >>>gnuplot-py-1.7-1
> >>>SciPy 0.4.4
> >>>
> >>>It wouldnt plot if i do this:
> >>>=================================
> >>>from scipy import linspace
> >>>import Gnuplot
> >>>g = Gnuplot.Gnuplot(debug = 1)
> >>>x = linspace(0, 1, 20).astype('f')        # i.e. array(0.0, 0.05, 0.10, ... 1.0)
> >>>y = linspace(0, 5, 20).astype('f')
> >>>d = Gnuplot.Data(x, y)
> >>>g.plot(d)
> >>>=================================
> >>>
> >>>
> >>Did you see an error message, or did it just do nothing? What version of Numeric
> >>do you have installed? I'm pretty sure the Gnuplot module still uses Numeric and
> >>may not recognize numpy arrays. Hopefully, it will try to do something like
> >>Numeric.asarray(x). If Numeric's version is >=24.0, that should automatically
> >>convert the numpy array to a Numeric array efficiently.
> >>
> >>--
> >>Robert Kern
> >>robert.kern at gmail.com
> >>
> >>"In the fields of hell where the grass grows high
> >> Are the graves of dreams allowed to die."
> >>  -- Richard Harter
> >>
> >>_______________________________________________
> >>SciPy-user mailing list
> >>SciPy-user at scipy.net
> >>http://www.scipy.net/mailman/listinfo/scipy-user
> >>
> >>
> >>
> >
> >
> >It opened a x11 window, but nothing is plotted. Sometimes it complain
> >about the range. I have a feeling it is converting all float to int,
> >hence all zero and nothing to plot.
> >
> >It plots fine if i make x range >> than 1:
> >=================================
> >from scipy import linspace
> >import Gnuplot
> >g = Gnuplot.Gnuplot(debug = 1)
> >x = linspace(0, 10, 20).astype('f')        # Make the end point >> 1
> >y = linspace(0, 50, 20).astype('f')
> >d = Gnuplot.Data(x, y)
> >g.plot(d)
> >=================================
> >
> >Ahh, my Numeric version is '23.7'
> >
> >
>
> Earlier versions of Numeric didn't handle it well if the return of the
> __array__ method (which I suspect it is calling), was not an actual
> Numeric ArrayObject.     On 32-bit platforms, the ndarray ArrayObject
> structure is the same as the Numeric ArrayObject structure.  However,
> the PyArray_Descr structure is quite a bit different and so I'm sure the
> type information is wrong if Numeric is just trying to use the output of
> the __array__ method on the ndarray object.
>
> Numeric should have been checking the output of the __array__ method and
> raising an error.  I know this got changed at some point, but I'm not
> sure how early.
>
> -Travis
>
>
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>

Upgrade Numeric to 24.2, now everything is working.

Thanks for the quick response.

--
iCy-fLaME
The body maybe wounded, but it is the mind that hurts.


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