On 05/31/2011 08:37 AM, Benjamin Root wrote: > > > On Tue, May 31, 2011 at 1:28 PM, Eric Firing <efir...@hawaii.edu > <mailto:efir...@hawaii.edu>> wrote: > > On 05/31/2011 08:03 AM, Benjamin Root wrote: > > > > On Tue, May 31, 2011 at 12:58 PM, Eric Firing > <efir...@hawaii.edu <mailto:efir...@hawaii.edu> > <mailto:efir...@hawaii.edu <mailto:efir...@hawaii.edu>>> wrote: > > On 05/31/2011 05:50 AM, Benjamin Root wrote: > > > > > > On Tue, May 31, 2011 at 10:34 AM, Mannucci, Anthony J (335G) > > <anthony.j.mannu...@jpl.nasa.gov > <mailto:anthony.j.mannu...@jpl.nasa.gov> > <mailto:anthony.j.mannu...@jpl.nasa.gov > <mailto:anthony.j.mannu...@jpl.nasa.gov>> > > <mailto:anthony.j.mannu...@jpl.nasa.gov > <mailto:anthony.j.mannu...@jpl.nasa.gov> > <mailto:anthony.j.mannu...@jpl.nasa.gov > <mailto:anthony.j.mannu...@jpl.nasa.gov>>>> wrote: > > > > The following program seems to work with contour/contourf. > However > > the documentation for the contourf function states > > > > contour(X,Y,Z) > > > > "/X/, /Y/, and /Z/ must be arrays with the same dimensions." > > > > I am finding that contour works if the dimension of X and Y > are 1, > > but Z must be two-dimensional. The following program seems to > bear > > this out. Are the arrays x and y below two-dimensional, > or is the > > documentation misleading? Thanks for your help. > > > > import numpy as N > > import pylab as PLT > > > > lons = N.linspace(-5.,5.,5) # Is this a one or two > dimensional array? > > lats = N.linspace(-3.,3.,4) > > > > z = N.zeros((len(lats), len(lons))) > > for i in range(len(lons)): > > for j in range(len(lats)): > > z[j,i]=i+j > > > > PLT.clf() > > PLT.contourf(lons,lats,z) > > PLT.colorbar() > > PLT.show() > > > > -Tony > > > > > > Tony, > > > > contour and contourf seems to take advantage of numpy's > broadcasting > > feature, so it is probably more correct to say that X and Y must > be at > > least broadcastable to the shape of Z. I think there are a > number of > > Not quite; if x and y are 1-D, meshgrid is called to make > 2-D versions, > which must then match Z. Broadcasting is not used or > supported. So, the > contour docstring was not updated when this functionality > was added, > long ago. Consider it an undocumented feature, in need of > documentation. > > Eric > > > Well, (as a bit of a cop-out) in my edit, I didn't say that they > were > broadcasted, only that they must be broadcastable to the same shape. > Would that suffice, or should I re-word that? > > > It would not be correct. > > x and y must both be 2-D, with the same shape as z; or they must > both be 1-D such that len(x) is the number of columns in z and > len(y) is the number of rows. > > Eric > > > Gotcha, I didn't think about the mixed 1-D and 2-D case. > > In addition, is the note in the contour doc about masked arrays still > valid, or can this be removed/updated? > > "*Z* may be a masked array, but filled contouring may not handle > internal masked regions correctly."
Good catch. Ian Thomas fixed the contouring algorithm so that it handles masked regions perfectly. Eric > > Ben Root > ------------------------------------------------------------------------------ Simplify data backup and recovery for your virtual environment with vRanger. Installation's a snap, and flexible recovery options mean your data is safe, secure and there when you need it. Data protection magic? Nope - It's vRanger. Get your free trial download today. http://p.sf.net/sfu/quest-sfdev2dev _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
