Eric, the GrADS interface is called 'pygrads'. it was developed by arlindo da silva of the 'opengrads' project; a project aimed at extending & enhancing the capabilities of grads by adding 'extensions' to the core grads engine. Many users are switching to plotting with pygrads due to the fact that matplotlib is a much richer, more powerful, more mature/extensive plotting environment. So, GrADS users can manipulate gridded data in grads, export through pygrads, and create nicer/more elaborate plots using matplotlib ;) http://opengrads.org/wiki/index.php?title=Python_Interface_to_GrADS as for the solution you offered, I tried doing the following: cs = m.contourf(X,Y,Z.filled(),Lv,norm=norm,cmap=plt.cm.jet) but I still got a plot with the '0.0' (land) areas plotted as 'white'/missing?. Does it matter that the output I provided from the "Z.mask" command showed all 'false' for the mask array? Is there any other info about the 'Z' grads-masked array that I can provide that might help figure out what is going wrong?
Pablo ---------------------------------------- > Date: Sun, 15 Mar 2009 18:01:08 -1000 > From: efir...@hawaii.edu > Subject: Re: [Matplotlib-users] FW: basemap.contourf, colormap, > extend='none', & levels array question > To: romero...@hotmail.com > CC: matplotlib-users@lists.sourceforge.net > > Pablo Romero wrote: >> it appears to be a masked array, but a "customized" one, that's being >> created from the interface to the external program Im working with >> (application named GrADS). here's some more info... >> > > Aha, very interesting! I know about grads but don't use it, and I did > not know about the python interface. > > Out of curiosity, why are you using the grads data interface but not the > grads plotting? > >> [7] ga-> Z? >> Type: GaField >> Base Class: >> String Form: >> [[0.0 0.0 0.0 ..., 0.0 0.0 0.0] >> [0.0 0.0 0.0 ..., 0.0 0.0 0.0] >> [0.0 0.0 0.0 ..., 0.0 0.0 0.0] >> 1.97999989986 ..., 0.924000024796 >> 1.41899991035 1.58399999142] >> [0.0 0.0 0.0 ..., 0.0 0.0 0.0]] >> Namespace: Interactive >> Length: 311 >> File: /usr/lib/python2.5/site-packages/grads/numtypes.py >> Docstring: >> This is GraDS version of a n-dimensional array: a masked array with >> a *grid* containing coordinate/dimension information attached to it. >> As a MaskedArray, GaField objects may possibly have masked values. >> Masked values of 1 exclude the corresponding element from any >> computation. >> Construction: >> x = GaField (data, name=None, Grid=None, >> dtype=None, copy=True, order=False, >> mask = nomask, fill_value=None) >> If copy=False, every effort is made not to copy the data: >> If data is a MaskedArray, and argument mask=nomask, >> then the candidate data is data.data and the >> mask used is data.mask. If data is a numeric array, >> it is used as the candidate raw data. >> If dtype is not None and >> is != data.dtype.char then a data copy is required. >> Otherwise, the candidate is used. >> If a data copy is required, raw data stored is the result of: >> numeric.array(data, dtype=dtype.char, copy=copy) >> If mask is nomask there are no masked values. Otherwise mask must >> be convertible to an array of booleans with the same shape as x. >> fill_value is used to fill in masked values when necessary, >> such as when printing and in method/function filled(). >> The fill_value is not used for computation within this module. >> >> >> [8] ga-> Z.mask >> Out[8]: >> array([[False, False, False, ..., False, False, False], >> [False, False, False, ..., False, False, False], >> [False, False, False, ..., False, False, False], >> ..., >> [False, False, False, ..., False, False, False], >> [False, False, False, ..., False, False, False], >> [False, False, False, ..., False, False, False]], dtype=bool) >> >> >> [12] ga-> np.linalg.norm([Z[0,0], Z[0,-1], Z[-1,0], Z[-1,-1]]) >> Out[12]: 0.0 > > > What I meant was the BoundaryNorm instance "norm" that you are using to > contour. But that's OK; we don't need that diagnostic now. > > The mystery is solved; the 0 values in your Z array are not really 0, > they are masked, and contourf is handling them correctly. 0.0 is just > the fill value. If you want that to be the *real* value, then instead of > using Z as the argument to your contourf call, use Z.filled(). > > Eric _________________________________________________________________ Windows Live™ Groups: Create an online spot for your favorite groups to meet. http://windowslive.com/online/groups?ocid=TXT_TAGLM_WL_groups_032009 ------------------------------------------------------------------------------ Apps built with the Adobe(R) Flex(R) framework and Flex Builder(TM) are powering Web 2.0 with engaging, cross-platform capabilities. Quickly and easily build your RIAs with Flex Builder, the Eclipse(TM)based development software that enables intelligent coding and step-through debugging. Download the free 60 day trial. http://p.sf.net/sfu/www-adobe-com _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
