host pointer to complex array?

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Joe Georger

Jul 26, 2017, 10:21:05 AM7/26/17
to ArrayFire Users
For debugging purposes I'm trying to bring a complex array back to the host:

        std::complex<float> *h_E =<std::complex<float> >();
        std::cout << h_E[0] << std::endl;
        delete [] h_E;

and I'm getting the following error:

Undefined symbols for architecture x86_64:
  "std::__1::complex<float>* af::array::host<std::__1::complex<float> >() const", referenced from:
      _main in test_kron.cpp.o
ld: symbol(s) not found for architecture x86_64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I'm using 
ArrayFire v3.5.0 (CPU, 64-bit Mac OSX, build 05999f3)
[0] Intel: Intel(R) Core(TM) i7-4980HQ CPU @ 2.80GHz, 16384 MB, Max threads(8).

Anyone encounter this?  I've tried with just float and it works fine....

Umar Arshad

Jul 26, 2017, 10:55:11 AM7/26/17
to ArrayFire Users
Hey Joe,

ArrayFire does not have a host function that converts directly to std::complex. You probably can do something like this:

vector<std::complex<float>> Edata(E.elements);;

Pavan Yalamanchili

Jul 26, 2017, 12:55:01 PM7/26/17
to Umar Arshad, ArrayFire Users
ArrayFire also implements a custom complex data type. This was done so arrayfire will not depend on the STL implementation which will cause incompatibilities between compiler versions.

If you wanted, you can use af::cfloat instead of std::complex<float>.

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Pradeep Garigipati

Jul 7, 2021, 12:41:36 AM7/7/21
to John Doe, ArrayFire Users
That is unexpected, here is a full blown standalone example code (followed by the sample output) that works fine.

#include <arrayfire.h>
#include <complex>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <algorithm>
#include <iterator>
#include <iostream>
#include <vector>

using namespace af;

int main(int argc, char* argv[]) {
    try {
        int device = argc > 1 ? atoi(argv[1]) : 0;

        array A = randu(5, 3, c32);

        std::vector< std::complex<float> > hostca(A.elements());;

        std::ostream_iterator< std::complex<float> > out_it(std::cout,", ");
        std::copy(hostca.begin(), hostca.end(), out_it);
    } catch (af::exception& e) {
        fprintf(stderr, "%s\n", e.what());

    return 0;

ArrayFire v3.9.0 (CPU, 64-bit Linux, build 293601beb)
[0] AMD: AMD A10-7850K Radeon R7, 12 Compute Cores 4C+8GA
[5 3 1 1]
   Offset: 0
   Strides: [1 5 15 15]
(0.6010,0.0278) (0.1583,0.3712) (0.6755,0.6105)
(0.9806,0.2126) (0.3543,0.6450) (0.5232,0.5567)
(0.0655,0.5497) (0.9675,0.3636) (0.7896,0.8966)
(0.2864,0.3410) (0.4165,0.5814) (0.0536,0.5775)
(0.7509,0.4105) (0.8962,0.3712) (0.2908,0.9941)

(0.601,0.02776), (0.9806,0.2126), (0.06546,0.5497), (0.2864,0.341), (0.7509,0.4105), (0.1583,0.3712), (0.3543,0.645), (0.9675,0.3636), (0.4165,0.5814), (0.8962,0.3712), (0.6755,0.6105), (0.5232,0.5567), (0.7896,0.8966), (0.05364,0.5775), (0.2908,0.9941)

On Fri, Jun 25, 2021 at 1:01 PM John Doe <> wrote:
The example from Umar doesn't work.

Could you provide a working compilable example please?


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