Joe and list, This is off topic, but can you point me to good documentation on the use of '&' as opposed to numpy.logical_and ?
Thanks, Sterling On Aug 28, 2014, at 7:18PM, Joe Kington wrote: > Why not just use boolean indexing? > > E.g. to find the region that falls between 5 and 10, do "(z >=5) & (z <= 10)": > > In [1]: import numpy as np > > In [2]: x, y = np.mgrid[-10:10, -10:10] > > In [3]: z = np.hypot(x, y) > > In [4]: result = (z >= 5) & (z <= 10) > > In [5]: result.astype(int) > Out[5]: > array([[0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0], > [0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0], > [0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0], > [0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0], > [0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0], > [0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0], > [0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1], > [1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1], > [0, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1], > [0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0], > [0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0], > [0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0], > [0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0], > [0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0]]) > > Cheers, > -Joe > > > > On Thu, Aug 28, 2014 at 8:23 PM, Eric Firing <efir...@hawaii.edu> wrote: > On 2014/08/28, 3:02 AM, Matthew Czesarski wrote: > > Hi Matplotlib Users! > > > > > > > > I have some 2-d arrays, which i am displaying with implot, and deriving > > contours for with contour. Easy - I'm just pulling them out of > > collections[0].get_paths() . > > > > However what's not easy is that I would like to recover a 1-0 or > > True-False array of the array values (pixels) that fall within the > > contours. Some line crossing algorithm/floodfill could do it, but I > > guess that matplotlib's fill() or contourf() must do this under the hood > > anyway. I've looked into the output both functions, but I don't see > > anything obvious.. > > > > Does anybody know if there's an a way to pull out a such an array from > > matplotlib? Any pointers are appreciated! > > Make an array of (x, y) pairs from the X and Y you use in your call to > contour, and then feed that array to the contains_points() method of > your contour Path. This will give you the desired Boolean array for any > given Path; depending on what you want, you might need to combine arrays > for more than one Path. > > To get closed paths, I think you will want to use contourf, not contour. > > Eric > > > > > > > Cheers, > > Matt > > > > > > ------------------------------------------------------------------------------ > > Slashdot TV. > > Video for Nerds. Stuff that matters. > > http://tv.slashdot.org/ > > > > > > > > _______________________________________________ > > Matplotlib-users mailing list > > Matplotlib-users@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > > > > ------------------------------------------------------------------------------ > Slashdot TV. > Video for Nerds. Stuff that matters. > http://tv.slashdot.org/ > _______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users > > ------------------------------------------------------------------------------ > Slashdot TV. > Video for Nerds. Stuff that matters. > http://tv.slashdot.org/_______________________________________________ > Matplotlib-users mailing list > Matplotlib-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/matplotlib-users ------------------------------------------------------------------------------ Slashdot TV. Video for Nerds. Stuff that matters. http://tv.slashdot.org/ _______________________________________________ Matplotlib-users mailing list Matplotlib-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/matplotlib-users
