Zachary Pincus wrote: > Hello all, > > I'm curious if people have experience with / preferences for how to > display a numpy array onscreen as an image. > > Pyglet looks relatively easy -- you can feed an image buffer object > with a string or a ctypes pointer. I presume getting a string from an > array is plenty fast, but the ctypes pointer option is intriguing as > it allows for dealing with simple strided arrays (the image objects > allow for an arbitrary number of bytes between rows). Is it possible > to get a ctypes pointer to the beginning of the array buffer from > numpy without too much ugliness?
In [16]: from numpy import * In [17]: a = arange(10) In [18]: dir(a.ctypes) Out[18]: ['__class__', '__delattr__', '__dict__', '__doc__', '__getattribute__', '__hash__', '__init__', '__module__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__str__', '__weakref__', '_arr', '_as_parameter_', '_ctypes', '_data', '_zerod', 'data', 'data_as', 'get_as_parameter', 'get_data', 'get_shape', 'get_strides', 'shape', 'shape_as', 'strides', 'strides_as'] In [22]: import ctypes In [24]: a.ctypes.data_as(ctypes.POINTER(ctypes.c_long)) Out[24]: <ctypes.LP_c_long object at 0x1b353a0> In [25]: a.ctypes.get_shape() Out[25]: <numpy.core._internal.c_long_Array_1 object at 0x1c096c0> In [26]: a.ctypes.get_strides() Out[26]: <numpy.core._internal.c_long_Array_1 object at 0x1c09710> In [27]: a.ctypes.get_as_parameter() Out[27]: c_void_p(27442576) You might want to use the new ctypes-based OpenGL 3.0+ package. It has numpy support a bit more directly. You can use Pyglet for its windowing and all of the other surrounding infrastructure and use OpenGL directly for the drawing. -- Robert Kern "I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth." -- Umberto Eco _______________________________________________ Numpy-discussion mailing list Numpy-discussion@scipy.org http://projects.scipy.org/mailman/listinfo/numpy-discussion
