--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/mex/mexnumtst.c	Fri Feb 21 17:15:40 2020 -0500
@@ -0,0 +1,91 @@
+#include <mex.h>
+
+// To be called with
+//
+//   single array
+//   complex single array
+//   double array
+//   complex double array
+//
+// Will return arrays of the same type, but created internally to test
+// the mxArray -> octave_value conversion
+
+void
+mexFunction (int nlhs, mxArray *plhs[],
+             int nrhs, const mxArray *prhs[])
+{
+  if (nrhs != 4 || nlhs != 4)
+    mexErrMsgTxt ("invalid arguments");
+
+  const mxArray *sngl_ra = prhs[0];
+  const mxArray *cplx_sngl_ra = prhs[1];
+  const mxArray *dble_ra = prhs[2];
+  const mxArray *cplx_dble_ra = prhs[3];
+
+#if MX_HAS_INTERLEAVED_COMPLEX
+
+  mxSingle *sngl_data = mxGetSingles (sngl_ra);
+  size_t sngl_data_nr = mxGetM (sngl_ra);
+  size_t sngl_data_nc = mxGetN (sngl_ra);
+
+  plhs[0] = mxCreateNumericMatrix (sngl_data_nr, sngl_data_nc, mxSINGLE_CLASS, mxREAL);
+  mxSetSingles (plhs[0], sngl_data);
+
+  mxComplexSingle *cplx_sngl_data = mxGetComplexSingles (cplx_sngl_ra);
+  size_t cplx_sngl_data_nr = mxGetM (cplx_sngl_ra);
+  size_t cplx_sngl_data_nc = mxGetN (cplx_sngl_ra);
+
+  plhs[1] = mxCreateNumericMatrix (cplx_sngl_data_nr, cplx_sngl_data_nc, mxSINGLE_CLASS, mxCOMPLEX);
+  mxSetComplexSingles (plhs[1], cplx_sngl_data);
+
+  mxDouble *dble_data = mxGetDoubles (dble_ra);
+  size_t dble_data_nr = mxGetM (dble_ra);
+  size_t dble_data_nc = mxGetN (dble_ra);
+
+  plhs[2] = mxCreateNumericMatrix (dble_data_nr, dble_data_nc, mxDOUBLE_CLASS, mxREAL);
+  mxSetDoubles (plhs[2], dble_data);
+
+  mxComplexDouble *cplx_dble_data = mxGetComplexDoubles (cplx_dble_ra);
+  size_t cplx_dble_data_nr = mxGetM (cplx_dble_ra);
+  size_t cplx_dble_data_nc = mxGetN (cplx_dble_ra);
+
+  plhs[3] = mxCreateNumericMatrix (cplx_dble_data_nr, cplx_dble_data_nc, mxDOUBLE_CLASS, mxCOMPLEX);
+  mxSetComplexDoubles (plhs[3], cplx_dble_data);
+
+#else
+
+  mxSingle *sngl_data = (mxSingle *) mxGetData (sngl_ra);
+  size_t sngl_data_nr = mxGetM (sngl_ra);
+  size_t sngl_data_nc = mxGetN (sngl_ra);
+
+  mxSingle *cplx_sngl_data_real = (mxSingle *) mxGetData (cplx_sngl_ra);
+  mxSingle *cplx_sngl_data_imag = (mxSingle *) mxGetImagData (cplx_sngl_ra);
+  size_t cplx_sngl_data_nr = mxGetM (cplx_sngl_ra);
+  size_t cplx_sngl_data_nc = mxGetN (cplx_sngl_ra);
+
+  mxDouble *dble_data = (mxDouble *) mxGetData (dble_ra);
+  size_t dble_data_nr = mxGetM (dble_ra);
+  size_t dble_data_nc = mxGetN (dble_ra);
+
+  mxDouble *cplx_dble_data_real = (mxDouble *) mxGetData (cplx_dble_ra);
+  mxDouble *cplx_dble_data_imag = (mxDouble *) mxGetImagData (cplx_dble_ra);
+  size_t cplx_dble_data_nr = mxGetM (cplx_dble_ra);
+  size_t cplx_dble_data_nc = mxGetN (cplx_dble_ra);
+
+  plhs[0] = mxCreateNumericMatrix (sngl_data_nr, sngl_data_nc, mxSINGLE_CLASS, mxREAL);
+  mxSetData (plhs[0], sngl_data);
+
+  plhs[1] = mxCreateNumericMatrix (cplx_sngl_data_nr, cplx_sngl_data_nc, mxSINGLE_CLASS, mxCOMPLEX);
+  mxSetData (plhs[1], cplx_sngl_data_real);
+  mxSetImagData (plhs[1], cplx_sngl_data_imag);
+
+  plhs[2] = mxCreateNumericMatrix (dble_data_nr, dble_data_nc, mxDOUBLE_CLASS, mxREAL);
+  mxSetData (plhs[2], dble_data);
+
+  plhs[3] = mxCreateNumericMatrix (cplx_dble_data_nr, cplx_dble_data_nc, mxDOUBLE_CLASS, mxCOMPLEX);
+  mxSetData (plhs[3], cplx_dble_data_real);
+  mxSetImagData (plhs[3], cplx_dble_data_imag);
+
+#endif
+
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/test/mex/mexnumtst.tst	Fri Feb 21 17:15:40 2020 -0500
@@ -0,0 +1,11 @@
+%!test
+%! s = rand (3, 4, "single");
+%! sc = s + i * rand (3, 4, "single");
+%! d = rand (3, 4, "double");
+%! dc = d + i * rand (3, 4, "double");
+%!
+%! [sx, scx, dx, dcx] = mexnumtst (s, sc, d, dc);
+%! assert (s, sx)
+%! assert (sc, scx)
+%! assert (d, dx)
+%! assert (dc, dcx)

--- a/test/mex/module.mk	Tue Feb 18 13:16:41 2020 -0500
+++ b/test/mex/module.mk	Fri Feb 21 17:15:40 2020 -0500
@@ -1,11 +1,13 @@
 mex_TEST_FILES = \
   %reldir%/bug-54096.tst \
   %reldir%/bug-51725.tst \
+  %reldir%/mexnumtst.tst \
   $(MEX_TEST_SRC)
 
 MEX_TEST_SRC = \
   %reldir%/bug_54096.c \
-  %reldir%/bug_51725.c
+  %reldir%/bug_51725.c \
+  %reldir%/mexnumtst.c
 
 MEX_TEST_FUNCTIONS = $(MEX_TEST_SRC:%.c=%.mex)