Ryan Neve wrote: > Eric, > > Here's a pcolor plot of the same data: > contour_plot = pyplot.pcolor(x_grid,y_grid,z_grid_masked) > http://imgur.com/iL4k7.png
It looks to me like this is more suitable for showing your data than contourf would be. > > For contourf I'm using: > contour_plot = > pyplot.contourf(x_grid,y_grid,z_grid_masked,contour_levels,origin='upper',\ > extent=extent,cmap=pyplot.cm.jet) > > ... where there are 256 evenly spaced contour_levels. And again, I think contourf makes sense with 10-20 levels, but not with 256. > Note that we have many more points on the Y (depth) axis than the X > (time). Each Y axis column originally had about 50 irregularly spaced > data points, but I used scipy.interpolate.interp1d to make my grid even. > I then increased the density substantially to smooth the data. > I don't know if this matters. Do you really want to smooth it, or do you want to simply show the data? You have big jumps from one sample time to the next. I don't see that it makes sense to to smooth heavily in the vertical; but I don't know what kind of measurement you are plotting or for what purpose. > > I'm not familiar with pcolorfast & pcolormesh, but I'll look in to that > tomorrow. They are less general than pcolor, but much faster. Eric > > Many Thanks, > > -Ryan > > On Thu, Nov 12, 2009 at 1:11 PM, Eric Firing <efir...@hawaii.edu > <mailto:efir...@hawaii.edu>> wrote: > > Ryan Neve wrote: > > Thank you for the suggestion, but I couldn't see a difference > with "antialiased" either True or False. The lines between > contour levels remain. > I tried a different colormap (spectral) but it had the same > effect. I tried more color levels (256) but the effect got worse. > > I can't find any example pictures online of matplotlib's > contourf() producing a "smooth" plot, I know matlab's does it: > > http://www.mbari.org/bog/Projects/CentralCal/summary/images/m1_nuts_ts_contour.jpg > > > That looks to me like a pcolor plot, not a contourf plot, regardless > of what the file name says. And, maybe it is my eyes, but it looks > to me like there are artifacts in the colorbar. In any case, if you > are plotting a very densely sampled data set, you may want to use > the Axes.pcolorfast method or the pcolormesh function or method > instead of contourf. Contouring, filled or not, is suitable for > data in which you want to bring out a moderate number of regions, > not for data with highly complex structure and texture, or if you > want essentially a smooth color progression. > > Eric > > > > -Ryan > > > On Wed, Nov 11, 2009 at 5:08 PM, Eric Firing <efir...@hawaii.edu > <mailto:efir...@hawaii.edu> <mailto:efir...@hawaii.edu > <mailto:efir...@hawaii.edu>>> wrote: > > Ryan Neve wrote: > > Hello, > In my filled contour plot: http://imgur.com/vXoCL.png > There are faint lines between the contour levels. I think > they > are yellow since they disappear in the yellow parts of > the graph > and are most obvious in the red areas. Is there any way > to get > rid of these lines? The number of contour levels is > arbitrary, > and I don't need them emphasized with a moire pattern. > ------------------------------------------------------------------------------ Let Crystal Reports handle the reporting - Free Crystal Reports 2008 30-Day trial. Simplify your report design, integration and deployment - and focus on what you do best, core application coding. Discover what's new with Crystal Reports now. http://p.sf.net/sfu/bobj-july _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
