toCtypes

Utility routine used to convert a NumPy ndarray to a ctypes array.

Synopsis

toCtypes (ndarr, ctypes_array)

Required Arguments

tuple ndarr[[]] (Input)

NumPy ndarray of any dimension.

ctypes ctypes_array[] (Input)

ctypes array already created of the correct size to hold the elements in the ndarray.

Description

This routine is used to copy a NumPy ndarray. This is only needed inside user defined functions. Arrays passed to user defined functions are always passed in a ctypes array. However if you wish to pass this array to another routine which expects an ndarray as input, including other PyIMSL functions, then you can use the toNdarray utility to convert from ctypes to ndarray, and then if needed, toCtypes to copy the results back from the ndarray to the ctypes array before exiting the user function.

Note that this utility is imported from pyimsl.util.imslConvert.

Example

For an example of using this routine see the example for the PyIMSL math routine linSolDefCg, the relevant part of which is shown here in the user supplied function:

from pyimsl.util.imslConvert import toCtypes
from pyimsl.util.imslConvert import toNdarray
...
def amultp (p,z):
            ptmp = toNdarray(p, (n))
            ztmp=matMulRect ("A*x",
                                  aMatrix = a,
                                  xVector = ptmp)
            toCtypes(ztmp, z)