I'm working on getting the Sage matrices for real/complex doubles to use numpy as a backend. In this, I'm using the PyArray_SETITEM macro from within Cython. However, Cython wraps the macro in a function call to convert the output to a Python value:
__pyx_1 = PyInt_FromLong(PyArray_SETITEM(__pyx_v_self->_matrix_numpy, PyArray_GETPTR2(__pyx_v_self->_matrix_numpy, __pyx_v_i, __pyx_v_j), __pyx_v_value)); However, after preprocessing, because of the semicolon at the end of the SETITEM macro, we get: PyInt_FromLong(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->descr->f->setitem((PyObject *)(__pyx_v_value), (char *)(((void *)((((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->data) + (__pyx_v_i)*(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->strides)[0] + (__pyx_v_j)*(((PyArrayObject *)(__pyx_v_self->_matrix_numpy))->strides)[1]))), (PyArrayObject *)(__pyx_v_self->_matrix_numpy));); Note that at the end, we have a "););". The file refuses to compile. Presumably, since SETITEM returns a value, wrapping the return value in a function call seems to be a reasonable thing to do. Would there be a problem in eliminating the semicolon and instead wrapping the entire function body in parenthesis? I noticed that GETITEM also ended in a semicolon, though I didn't have the same problem as above since Cython didn't automatically wrap it in a function call (I'm not even sure if it returns something). On a side note, is the above the best way (i.e., fastest way given an arbitrary numpy array) to set/get an element? Thanks, Jason _______________________________________________ Numpy-discussion mailing list [email protected] http://projects.scipy.org/mailman/listinfo/numpy-discussion
