/*
 * Copyright (c) 1997-1999 Massachusetts Institute of Technology
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 * fftw_test.c : test program for complex-complex transforms
 */

/* $Id: rfftw_test.c,v 1.23 1999/05/05 22:15:11 fftw Exp $ */
#include <fftw-int.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <math.h>
#include <time.h>

#include <rfftw.h>

#include "test_main.h"

char fftw_prefix[] = "rfftw";

/*************************************************
 * Speed tests
 *************************************************/

void zero_arr(int n, fftw_real * a)
{
     int i;
     for (i = 0; i < n; ++i)
	  a[i] = 0.0;
}

void test_speed_aux(int n, fftw_direction dir, int flags, int specific)
{
     fftw_real *in, *out;
     fftw_plan plan;
     double t;
     fftw_time begin, end;

     in = (fftw_real *) fftw_malloc(n * howmany_fields
				    * sizeof(fftw_real));
     out = (fftw_real *) fftw_malloc(n * howmany_fields
				     * sizeof(fftw_real));

     if (specific) {
	  begin = fftw_get_time();
	  plan = rfftw_create_plan_specific(n, dir,
					speed_flag | flags | wisdom_flag,
					    in, howmany_fields,
					    out, howmany_fields);
	  end = fftw_get_time();
     } else {
	  begin = fftw_get_time();
	  plan = rfftw_create_plan(n, dir, speed_flag | flags | wisdom_flag);
	  end = fftw_get_time();
     }
     CHECK(plan != NULL, "can't create plan");

     t = fftw_time_to_sec(fftw_time_diff(end, begin));
     WHEN_VERBOSE(2, printf("time for planner: %f s\n", t));

     WHEN_VERBOSE(2, rfftw_print_plan(plan));

     FFTW_TIME_FFT(rfftw(plan, howmany_fields,
			 in, howmany_fields, 1, out, howmany_fields, 1),
		   in, n * howmany_fields, t);

     rfftw_destroy_plan(plan);

     WHEN_VERBOSE(1, printf("time for one fft: %s", smart_sprint_time(t)));
     WHEN_VERBOSE(1, printf(" (%s/point)\n", smart_sprint_time(t / n)));
     WHEN_VERBOSE(1, printf("\"mflops\" = 5/2 (n log2 n) / (t in microseconds)"
			" = %f\n", 0.5 * howmany_fields * mflops(t, n)));

     fftw_free(in);
     fftw_free(out);

     WHEN_VERBOSE(1, printf("\n"));
}

void test_speed_nd_aux(struct size sz,
		       fftw_direction dir, int flags, int specific)
{
     fftw_real *in;
     fftwnd_plan plan;
     double t;
     fftw_time begin, end;
     int i, N;

     /* only bench in-place multi-dim transforms */
     flags |= FFTW_IN_PLACE;	

     N = 1;
     for (i = 0; i < sz.rank - 1; ++i)
	  N *= sz.narray[i];

     N *= (sz.narray[i] + 2);

     in = (fftw_real *) fftw_malloc(N * howmany_fields * sizeof(fftw_real));

     if (specific) {
	  begin = fftw_get_time();
	  plan = rfftwnd_create_plan_specific(sz.rank, sz.narray, dir,
					speed_flag | flags | wisdom_flag,
					      in, howmany_fields, 0, 1);
     } else {
	  begin = fftw_get_time();
	  plan = rfftwnd_create_plan(sz.rank, sz.narray,
				  dir, speed_flag | flags | wisdom_flag);
     }
     end = fftw_get_time();
     CHECK(plan != NULL, "can't create plan");

     t = fftw_time_to_sec(fftw_time_diff(end, begin));
     WHEN_VERBOSE(2, printf("time for planner: %f s\n", t));

     WHEN_VERBOSE(2, printf("\n"));
     WHEN_VERBOSE(2, (rfftwnd_print_plan(plan)));
     WHEN_VERBOSE(2, printf("\n"));

     if (dir == FFTW_REAL_TO_COMPLEX) {
	  FFTW_TIME_FFT(rfftwnd_real_to_complex(plan, howmany_fields,
						in, howmany_fields, 1,
						0, 0, 0),
			in, N * howmany_fields, t);
     } else {
	  FFTW_TIME_FFT(rfftwnd_complex_to_real(plan, howmany_fields,
						(fftw_complex *) in,
						howmany_fields, 1,
						0, 0, 0),
			in, N * howmany_fields, t);
     }

     rfftwnd_destroy_plan(plan);

     WHEN_VERBOSE(1, printf("time for one fft: %s", smart_sprint_time(t)));
     WHEN_VERBOSE(1, printf(" (%s/point)\n", smart_sprint_time(t / N)));
     WHEN_VERBOSE(1, printf("\"mflops\" = 5/2 (N log2 N) / (t in microseconds)"
			" = %f\n", 0.5 * howmany_fields * mflops(t, N)));

     fftw_free(in);

     WHEN_VERBOSE(1, printf("\n"));
}

/*************************************************
 * correctness tests
 *************************************************/

void fill_random(fftw_real * a, int n, int stride)
{
     int i;

     /* generate random inputs */
     for (i = 0; i < n; ++i)
	  a[i * stride] = DRAND();
}

double compute_error(fftw_real * A, int astride,
		     fftw_real * B, int bstride, int n)
{
     /* compute the relative error */
     double error = 0.0;
     int i;

     for (i = 0; i < n; ++i) {
	  double a;
	  double mag;
	  a = fabs(A[i * astride] - B[i * bstride]);
	  mag = 0.5 * (fabs(A[i * astride]) + fabs(B[i * bstride])) + TOLERANCE;

	  a /= mag;
	  if (a > error)
	       error = a;

#ifdef HAVE_ISNAN
	  CHECK(!isnan(a), "NaN in answer");
#endif
     }
     return error;
}

void array_compare(fftw_real * A, fftw_real * B, int n)
{
     CHECK(compute_error(A, 1, B, 1, n) < TOLERANCE,
	   "failure in RFFTW verification");
}

void test_out_of_place(int n, int istride, int ostride,
		       int howmany, fftw_direction dir,
		       fftw_plan validated_plan, int specific)
{
     fftw_complex *in2, *out2;
     fftw_real *in1, *out1, *out3;
     fftw_plan plan;
     int i, j;
     int flags = measure_flag | wisdom_flag;

     if (coinflip())
	  flags |= FFTW_THREADSAFE;

     in1 = (fftw_real *) fftw_malloc(istride * n * sizeof(fftw_real) * howmany);
     in2 = (fftw_complex *) fftw_malloc(n * sizeof(fftw_complex));
     out1 = (fftw_real *) fftw_malloc(ostride * n * sizeof(fftw_real) * howmany);
     out2 = (fftw_complex *) fftw_malloc(n * sizeof(fftw_complex));
     out3 = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));

     if (!specific)
	  plan = rfftw_create_plan(n, dir, flags);
     else
	  plan = rfftw_create_plan_specific(n, dir, flags,
					    in1, istride, out1, ostride);
     CHECK(plan != NULL, "can't create plan");

     /* generate random inputs */
     fill_random(in1, n, istride);
     for (j = 1; j < howmany; ++j)
	  for (i = 0; i < n; ++i)
	       in1[(j * n + i) * istride] = in1[i * istride];

     /* copy random inputs to complex array for comparison with fftw: */
     if (dir == FFTW_REAL_TO_COMPLEX)
	  for (i = 0; i < n; ++i) {
	       c_re(in2[i]) = in1[i * istride];
	       c_im(in2[i]) = 0.0;
     } else {
	  int n2 = (n + 1) / 2;
	  c_re(in2[0]) = in1[0];
	  c_im(in2[0]) = 0.0;
	  for (i = 1; i < n2; ++i) {
	       c_re(in2[i]) = in1[i * istride];
	       c_im(in2[i]) = in1[(n - i) * istride];
	  }
	  if (n2 * 2 == n) {
	       c_re(in2[n2]) = in1[n2 * istride];
	       c_im(in2[n2]) = 0.0;
	       ++i;
	  }
	  for (; i < n; ++i) {
	       c_re(in2[i]) = c_re(in2[n - i]);
	       c_im(in2[i]) = -c_im(in2[n - i]);
	  }
     }

     /* 
      * fill in other positions of the array, to make sure that
      * rfftw doesn't overwrite them 
      */
     for (j = 1; j < istride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       in1[i * istride + j] = i * istride + j;

     for (j = 1; j < ostride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       out1[i * ostride + j] = -i * ostride + j;

     WHEN_VERBOSE(2, rfftw_print_plan(plan));

     /* fft-ize */
     if (howmany != 1 || istride != 1 || ostride != 1 || coinflip())
	  rfftw(plan, howmany, in1, istride, n * istride, out1, ostride,
		n * ostride);
     else
	  rfftw_one(plan, in1, out1);

     rfftw_destroy_plan(plan);

     /* check for overwriting */
     for (j = 1; j < istride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       CHECK(in1[i * istride + j] == i * istride + j,
		     "input has been overwritten");
     for (j = 1; j < ostride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       CHECK(out1[i * ostride + j] == -i * ostride + j,
		     "output has been overwritten");

     fftw(validated_plan, 1, in2, 1, n, out2, 1, n);

     if (dir == FFTW_REAL_TO_COMPLEX) {
	  int n2 = (n + 1) / 2;
	  out3[0] = c_re(out2[0]);
	  for (i = 1; i < n2; ++i) {
	       out3[i] = c_re(out2[i]);
	       out3[n - i] = c_im(out2[i]);
	  }
	  if (n2 * 2 == n)
	       out3[n2] = c_re(out2[n2]);
     } else {
	  for (i = 0; i < n; ++i)
	       out3[i] = c_re(out2[i]);
     }

     for (j = 0; j < howmany; ++j)
	  CHECK(compute_error(out1 + j * n * ostride, ostride, out3, 1, n)
		< TOLERANCE,
		"test_out_of_place: wrong answer");
     WHEN_VERBOSE(2, printf("OK\n"));

     fftw_free(in1);
     fftw_free(in2);
     fftw_free(out1);
     fftw_free(out2);
     fftw_free(out3);
}

void test_in_place(int n, int istride,
		   int howmany, fftw_direction dir,
		   fftw_plan validated_plan, int specific)
{
     fftw_complex *in2, *out2;
     fftw_real *in1, *out1, *out3;
     fftw_plan plan;
     int i, j;
     int ostride = istride;
     int flags = measure_flag | wisdom_flag | FFTW_IN_PLACE;

     if (coinflip())
	  flags |= FFTW_THREADSAFE;

     in1 = (fftw_real *) fftw_malloc(istride * n * sizeof(fftw_real) * howmany);
     in2 = (fftw_complex *) fftw_malloc(n * sizeof(fftw_complex));
     out1 = in1;
     out2 = (fftw_complex *) fftw_malloc(n * sizeof(fftw_complex));
     out3 = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));

     if (!specific)
	  plan = rfftw_create_plan(n, dir, flags);
     else
	  plan = rfftw_create_plan_specific(n, dir, flags,
					    in1, istride, out1, ostride);
     CHECK(plan != NULL, "can't create plan");

     /* generate random inputs */
     fill_random(in1, n, istride);
     for (j = 1; j < howmany; ++j)
	  for (i = 0; i < n; ++i)
	       in1[(j * n + i) * istride] = in1[i * istride];

     /* copy random inputs to complex array for comparison with fftw: */
     if (dir == FFTW_REAL_TO_COMPLEX)
	  for (i = 0; i < n; ++i) {
	       c_re(in2[i]) = in1[i * istride];
	       c_im(in2[i]) = 0.0;
     } else {
	  int n2 = (n + 1) / 2;
	  c_re(in2[0]) = in1[0];
	  c_im(in2[0]) = 0.0;
	  for (i = 1; i < n2; ++i) {
	       c_re(in2[i]) = in1[i * istride];
	       c_im(in2[i]) = in1[(n - i) * istride];
	  }
	  if (n2 * 2 == n) {
	       c_re(in2[n2]) = in1[n2 * istride];
	       c_im(in2[n2]) = 0.0;
	       ++i;
	  }
	  for (; i < n; ++i) {
	       c_re(in2[i]) = c_re(in2[n - i]);
	       c_im(in2[i]) = -c_im(in2[n - i]);
	  }
     }

     /* 
      * fill in other positions of the array, to make sure that
      * rfftw doesn't overwrite them 
      */
     for (j = 1; j < istride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       in1[i * istride + j] = i * istride + j;

     WHEN_VERBOSE(2, rfftw_print_plan(plan));

     /* fft-ize */
     if (howmany != 1 || istride != 1 || coinflip())
	  rfftw(plan, howmany, in1, istride, n * istride, 0, 0, 0);
     else
	  rfftw_one(plan, in1, NULL);

     rfftw_destroy_plan(plan);

     /* check for overwriting */
     for (j = 1; j < ostride; ++j)
	  for (i = 0; i < n * howmany; ++i)
	       CHECK(out1[i * ostride + j] == i * ostride + j,
		     "output has been overwritten");

     fftw(validated_plan, 1, in2, 1, n, out2, 1, n);

     if (dir == FFTW_REAL_TO_COMPLEX) {
	  int n2 = (n + 1) / 2;
	  out3[0] = c_re(out2[0]);
	  for (i = 1; i < n2; ++i) {
	       out3[i] = c_re(out2[i]);
	       out3[n - i] = c_im(out2[i]);
	  }
	  if (n2 * 2 == n)
	       out3[n2] = c_re(out2[n2]);
     } else {
	  for (i = 0; i < n; ++i)
	       out3[i] = c_re(out2[i]);
     }

     for (j = 0; j < howmany; ++j)
	  CHECK(compute_error(out1 + j * n * ostride, ostride, out3, 1, n)
		< TOLERANCE,
		"test_in_place: wrong answer");
     WHEN_VERBOSE(2, printf("OK\n"));

     fftw_free(in1);
     fftw_free(in2);
     fftw_free(out2);
     fftw_free(out3);
}

void test_out_of_place_both(int n, int istride, int ostride,
			    int howmany,
			    fftw_plan validated_plan_forward,
			    fftw_plan validated_plan_backward)
{
     int specific;

     for (specific = 0; specific <= 1; ++specific) {
	  WHEN_VERBOSE(2,
	       printf("TEST CORRECTNESS (out of place, FFTW_FORWARD, %s)"
		   " n = %d  istride = %d  ostride = %d  howmany = %d\n",
		      SPECIFICP(specific),
		      n, istride, ostride, howmany));
	  test_out_of_place(n, istride, ostride, howmany, FFTW_FORWARD,
			    validated_plan_forward, specific);

	  WHEN_VERBOSE(2,
	      printf("TEST CORRECTNESS (out of place, FFTW_BACKWARD, %s)"
		   " n = %d  istride = %d  ostride = %d  howmany = %d\n",
		     SPECIFICP(specific),
		     n, istride, ostride, howmany));
	  test_out_of_place(n, istride, ostride, howmany, FFTW_BACKWARD,
			    validated_plan_backward, specific);
     }
}

void test_in_place_both(int n, int istride, int howmany,
			fftw_plan validated_plan_forward,
			fftw_plan validated_plan_backward)
{
     int specific;

     for (specific = 0; specific <= 1; ++specific) {
	  WHEN_VERBOSE(2,
		  printf("TEST CORRECTNESS (in place, FFTW_FORWARD, %s) "
			 "n = %d  istride = %d  howmany = %d\n",
			 SPECIFICP(specific),
			 n, istride, howmany));
	  test_in_place(n, istride, howmany, FFTW_FORWARD,
			validated_plan_forward, specific);

	  WHEN_VERBOSE(2,
		 printf("TEST CORRECTNESS (in place, FFTW_BACKWARD, %s) "
			"n = %d  istride = %d  howmany = %d\n",
			SPECIFICP(specific),
			n, istride, howmany));
	  test_in_place(n, istride, howmany, FFTW_BACKWARD,
			validated_plan_backward, specific);
     }
}

void test_correctness(int n)
{
     int istride, ostride, howmany;
     fftw_plan validated_plan_forward, validated_plan_backward;

     WHEN_VERBOSE(1,
		  printf("Testing correctness for n = %d...", n);
		  fflush(stdout));

     /* produce a *good* plan (validated by Ergun's test procedure) */
     validated_plan_forward =
	 fftw_create_plan(n, FFTW_FORWARD, measure_flag | wisdom_flag);
     validated_plan_backward =
	 fftw_create_plan(n, FFTW_BACKWARD, measure_flag | wisdom_flag);
     CHECK(validated_plan_forward != NULL, "can't create plan");
     CHECK(validated_plan_backward != NULL, "can't create plan");

     for (istride = 1; istride <= MAX_STRIDE; ++istride)
	  for (ostride = 1; ostride <= MAX_STRIDE; ++ostride)
	       for (howmany = 1; howmany <= MAX_HOWMANY; ++howmany)
		    test_out_of_place_both(n, istride, ostride, howmany,
					   validated_plan_forward,
					   validated_plan_backward);

     for (istride = 1; istride <= MAX_STRIDE; ++istride)
	  for (howmany = 1; howmany <= MAX_HOWMANY; ++howmany)
	       test_in_place_both(n, istride, howmany,
				  validated_plan_forward,
				  validated_plan_backward);

     fftw_destroy_plan(validated_plan_forward);
     fftw_destroy_plan(validated_plan_backward);

     if (!(wisdom_flag & FFTW_USE_WISDOM) && chk_mem_leak)
	  fftw_check_memory_leaks();

     WHEN_VERBOSE(1, printf("OK\n"));
}

/*************************************************
 * multi-dimensional correctness tests
 *************************************************/

void testnd_out_of_place(int rank, int *n, fftwnd_plan validated_plan)
{
     int istride, ostride;
     int N, dim, i, j, k;
     int nc, nhc, nr;
     fftw_real *in1, *out3;
     fftw_complex *in2, *out1, *out2;
     fftwnd_plan p, ip;
     int flags = measure_flag | wisdom_flag;

     if (coinflip())
	  flags |= FFTW_THREADSAFE;

     N = nc = nr = nhc = 1;
     for (dim = 0; dim < rank; ++dim)
	  N *= n[dim];
     if (rank > 0) {
	  nr = n[rank - 1];
	  nc = N / nr;
	  nhc = nr / 2 + 1;
     }
     in1 = (fftw_real *) fftw_malloc(N * MAX_STRIDE * sizeof(fftw_real));
     out3 = (fftw_real *) fftw_malloc(N * MAX_STRIDE * sizeof(fftw_real));
     out1 = (fftw_complex *) fftw_malloc(nhc * nc * MAX_STRIDE
					 * sizeof(fftw_complex));
     in2 = (fftw_complex *) fftw_malloc(N * sizeof(fftw_complex));
     out2 = (fftw_complex *) fftw_malloc(N * sizeof(fftw_complex));

     p = rfftwnd_create_plan(rank, n, FFTW_REAL_TO_COMPLEX, flags);
     ip = rfftwnd_create_plan(rank, n, FFTW_COMPLEX_TO_REAL, flags);
     CHECK(p != NULL && ip != NULL, "can't create plan");

     for (istride = 1; istride <= MAX_STRIDE; ++istride) {
	  /* generate random inputs */
	  for (i = 0; i < nc; ++i)
	       for (j = 0; j < nr; ++j) {
		    c_re(in2[i * nr + j]) = DRAND();
		    c_im(in2[i * nr + j]) = 0.0;
		    for (k = 0; k < istride; ++k)
			 in1[(i * nr + j) * istride + k]
			     = c_re(in2[i * nr + j]);
	       }
	  for (i = 0; i < N * istride; ++i)
	       out3[i] = 0.0;

	  fftwnd(validated_plan, 1, in2, 1, 1, out2, 1, 1);

	  for (ostride = 1; ostride <= MAX_STRIDE; ++ostride) {
	       int howmany = (istride < ostride) ? istride : ostride;

	       WHEN_VERBOSE(2, printf("\n    testing stride %d/%d...",
				      istride, ostride));

	       if (howmany != 1 || istride != 1 || ostride != 1 || coinflip())
		    rfftwnd_real_to_complex(p, howmany, in1, istride, 1,
					    out1, ostride, 1);
	       else
		    rfftwnd_one_real_to_complex(p, in1, out1);

	       for (i = 0; i < nc; ++i)
		    for (k = 0; k < howmany; ++k)
			 CHECK(compute_error_complex(out1 + i * nhc * ostride + k,
						     ostride,
						     out2 + i * nr, 1,
						     nhc) < TOLERANCE,
			       "out-of-place (r2c): wrong answer");

	       if (howmany != 1 || istride != 1 || ostride != 1 || coinflip())
		    rfftwnd_complex_to_real(ip, howmany, out1, ostride, 1,
					    out3, istride, 1);
	       else
		    rfftwnd_one_complex_to_real(ip, out1, out3);

	       for (i = 0; i < N * istride; ++i)
		    out3[i] *= 1.0 / N;

	       if (istride == howmany)
		    CHECK(compute_error(out3, 1, in1, 1, N * istride)
			< TOLERANCE, "out-of-place (c2r): wrong answer");
	       for (i = 0; i < nc; ++i)
		    for (k = 0; k < howmany; ++k)
			 CHECK(compute_error(out3 + i * nr * istride + k,
					     istride,
					 (fftw_real *) (in2 + i * nr), 2,
					     nr) < TOLERANCE,
			   "out-of-place (c2r): wrong answer (check 2)");
	  }
     }

     rfftwnd_destroy_plan(p);
     rfftwnd_destroy_plan(ip);

     fftw_free(out3);
     fftw_free(out2);
     fftw_free(in2);
     fftw_free(out1);
     fftw_free(in1);
}

void testnd_in_place(int rank, int *n, fftwnd_plan validated_plan,
		     int alternate_api, int specific)
{
     int istride, ostride, howmany;
     int N, dim, i, j, k;
     int nc, nhc, nr;
     fftw_real *in1, *out3;
     fftw_complex *in2, *out1, *out2;
     fftwnd_plan p, ip;
     int flags = measure_flag | wisdom_flag | FFTW_IN_PLACE;

     if (coinflip())
	  flags |= FFTW_THREADSAFE;

     N = nc = nr = nhc = 1;
     for (dim = 0; dim < rank; ++dim)
	  N *= n[dim];
     if (rank > 0) {
	  nr = n[rank - 1];
	  nc = N / nr;
	  nhc = nr / 2 + 1;
     }
     in1 = (fftw_real *) fftw_malloc(2 * nhc * nc * MAX_STRIDE * sizeof(fftw_real));
     out3 = in1;
     out1 = (fftw_complex *) in1;
     in2 = (fftw_complex *) fftw_malloc(N * sizeof(fftw_complex));
     out2 = (fftw_complex *) fftw_malloc(N * sizeof(fftw_complex));

     if (alternate_api && specific && (rank == 2 || rank == 3)) {
	  if (rank == 2) {
	       p = rfftw2d_create_plan_specific(n[0], n[1],
					     FFTW_REAL_TO_COMPLEX, flags,
						in1, MAX_STRIDE, 0, 0);
	       ip = rfftw2d_create_plan_specific(n[0], n[1],
					     FFTW_COMPLEX_TO_REAL, flags,
						 in1, MAX_STRIDE, 0, 0);
	  } else {
	       p = rfftw3d_create_plan_specific(n[0], n[1], n[2],
					     FFTW_REAL_TO_COMPLEX, flags,
						in1, MAX_STRIDE, 0, 0);
	       ip = rfftw3d_create_plan_specific(n[0], n[1], n[2],
					     FFTW_COMPLEX_TO_REAL, flags,
						 in1, MAX_STRIDE, 0, 0);
	  }
     } else if (specific) {
	  p = rfftwnd_create_plan_specific(rank, n, FFTW_REAL_TO_COMPLEX,
					   flags,
				       in1, MAX_STRIDE, in1, MAX_STRIDE);
	  ip = rfftwnd_create_plan_specific(rank, n, FFTW_COMPLEX_TO_REAL,
					    flags,
				       in1, MAX_STRIDE, in1, MAX_STRIDE);
     } else if (alternate_api && (rank == 2 || rank == 3)) {
	  if (rank == 2) {
	       p = rfftw2d_create_plan(n[0], n[1], FFTW_REAL_TO_COMPLEX,
				       flags);
	       ip = rfftw2d_create_plan(n[0], n[1], FFTW_COMPLEX_TO_REAL,
					flags);
	  } else {
	       p = rfftw3d_create_plan(n[0], n[1], n[2], FFTW_REAL_TO_COMPLEX,
				       flags);
	       ip = rfftw3d_create_plan(n[0], n[1], n[2], FFTW_COMPLEX_TO_REAL,
					flags);
	  }
     } else {
	  p = rfftwnd_create_plan(rank, n, FFTW_REAL_TO_COMPLEX, flags);
	  ip = rfftwnd_create_plan(rank, n, FFTW_COMPLEX_TO_REAL, flags);
     }

     CHECK(p != NULL && ip != NULL, "can't create plan");

     for (i = 0; i < nc * nhc * 2 * MAX_STRIDE; ++i)
	  out3[i] = 0;

     for (istride = 1; istride <= MAX_STRIDE; ++istride) {
	  /* generate random inputs */
	  for (i = 0; i < nc; ++i)
	       for (j = 0; j < nr; ++j) {
		    c_re(in2[i * nr + j]) = DRAND();
		    c_im(in2[i * nr + j]) = 0.0;
		    for (k = 0; k < istride; ++k)
			 in1[(i * nhc * 2 + j) * istride + k]
			     = c_re(in2[i * nr + j]);
	       }

	  fftwnd(validated_plan, 1, in2, 1, 1, out2, 1, 1);

	  howmany = ostride = istride;

	  WHEN_VERBOSE(2, printf("\n    testing in-place stride %d...",
				 istride));

	  if (howmany != 1 || istride != 1 || ostride != 1 || coinflip())
	       rfftwnd_real_to_complex(p, howmany, in1, istride, 1,
				       out1, ostride, 1);
	  else
	       rfftwnd_one_real_to_complex(p, in1, NULL);

	  for (i = 0; i < nc; ++i)
	       for (k = 0; k < howmany; ++k)
		    CHECK(compute_error_complex(out1 + i * nhc * ostride + k,
						ostride,
						out2 + i * nr, 1,
						nhc) < TOLERANCE,
			  "in-place (r2c): wrong answer");

	  if (howmany != 1 || istride != 1 || ostride != 1 || coinflip())
	       rfftwnd_complex_to_real(ip, howmany, out1, ostride, 1,
				       out3, istride, 1);
	  else
	       rfftwnd_one_complex_to_real(ip, out1, NULL);

	  for (i = 0; i < nc * nhc * 2 * istride; ++i)
	       out3[i] *= 1.0 / N;

	  for (i = 0; i < nc; ++i)
	       for (k = 0; k < howmany; ++k)
		    CHECK(compute_error(out3 + i * nhc * 2 * istride + k,
					istride,
					(fftw_real *) (in2 + i * nr), 2,
					nr) < TOLERANCE,
			  "in-place (c2r): wrong answer (check 2)");
     }

     rfftwnd_destroy_plan(p);
     rfftwnd_destroy_plan(ip);

     fftw_free(out2);
     fftw_free(in2);
     fftw_free(in1);
}

void testnd_correctness(struct size sz, fftw_direction dir,
			int alt_api, int specific, int force_buf)
{
     fftwnd_plan validated_plan;

     if (dir != FFTW_FORWARD)
	  return;
     if (force_buf)
	  return;

     validated_plan = fftwnd_create_plan(sz.rank, sz.narray, 
					 dir, measure_flag | wisdom_flag);
     CHECK(validated_plan != NULL, "can't create plan");

     testnd_out_of_place(sz.rank, sz.narray, validated_plan);
     testnd_in_place(sz.rank, sz.narray,
		     validated_plan, alt_api, specific);

     fftwnd_destroy_plan(validated_plan);
}

/*************************************************
 * planner tests
 *************************************************/

void test_planner(int rank)
{
     /* 
      * create and destroy many plans, at random.  Check the
      * garbage-collecting allocator of twiddle factors 
      */
     int i, dim;
     int r, s;
     fftw_plan p[PLANNER_TEST_SIZE];
     fftwnd_plan pnd[PLANNER_TEST_SIZE];
     int *narr, maxdim;

     chk_mem_leak = 0;
     verbose--;

     please_wait();
     if (rank < 1)
	  rank = 1;

     narr = (int *) fftw_malloc(rank * sizeof(int));

     maxdim = (int) pow(8192.0, 1.0/rank);

     for (i = 0; i < PLANNER_TEST_SIZE; ++i) {
	  p[i] = (fftw_plan) 0;
	  pnd[i] = (fftwnd_plan) 0;
     }

     for (i = 0; i < PLANNER_TEST_SIZE * PLANNER_TEST_SIZE; ++i) {
	  r = rand();
	  if (r < 0)
	       r = -r;
	  r = r % PLANNER_TEST_SIZE;

	  for (dim = 0; dim < rank; ++dim) {
	       do {
		    s = rand();
		    if (s < 0)
			 s = -s;
		    s = s % maxdim + 1;
	       } while (s == 0);
	       narr[dim] = s;
	  }

	  if (rank == 1) {
	       if (p[r])
		    rfftw_destroy_plan(p[r]);

	       p[r] = rfftw_create_plan(narr[0], random_dir(), measure_flag |
					wisdom_flag);
	       if (paranoid && narr[0] < 200)
		    test_correctness(narr[0]);
	  }
	  if (pnd[r])
	       rfftwnd_destroy_plan(pnd[r]);

	  pnd[r] = rfftwnd_create_plan(rank, narr,
				       random_dir(), measure_flag |
				       wisdom_flag);

	  if (i % (PLANNER_TEST_SIZE * PLANNER_TEST_SIZE / 20) == 0) {
	       WHEN_VERBOSE(0, printf("test planner: so far so good\n"));
	       WHEN_VERBOSE(0, printf("test planner: iteration %d out of %d\n",
			      i, PLANNER_TEST_SIZE * PLANNER_TEST_SIZE));
	  }
     }

     for (i = 0; i < PLANNER_TEST_SIZE; ++i) {
	  if (p[i])
	       rfftw_destroy_plan(p[i]);
	  if (pnd[i])
	       rfftwnd_destroy_plan(pnd[i]);
     }

     fftw_free(narr);
     verbose++;
     chk_mem_leak = 1;
}


/*************************************************
 * Ergun's test for real->complex transforms
 *************************************************/
static void rfill_random(fftw_real *a, int n)
{
     int i;

     for (i = 0; i < n; ++i) {
	  a[i] = DRAND();
     }
}

static void rarray_copy(fftw_real *out, fftw_real *in, int n)
{
     int i;

     for (i = 0; i < n; ++i)
	  out[i] = in[i];
}

/* C = A + B */
void rarray_add(fftw_real *C, fftw_real *A, fftw_real *B, int n)
{
     int i;

     for (i = 0; i < n; ++i) {
	  C[i] = A[i] + B[i];
     }
}

/* C = A - B */
void rarray_sub(fftw_real *C, fftw_real *A, fftw_real *B, int n)
{
     int i;

     for (i = 0; i < n; ++i) {
	  C[i] = A[i] - B[i];
     }
}

/* B = rotate left A */
void rarray_rol(fftw_real *B, fftw_real *A,
	       int n, int n_before, int n_after)
{
     int i, ib, ia;

     for (ib = 0; ib < n_before; ++ib) {
	  for (i = 0; i < n - 1; ++i)
	       for (ia = 0; ia < n_after; ++ia)
		    B[(ib * n + i) * n_after + ia] =
			A[(ib * n + i + 1) * n_after + ia];

	  for (ia = 0; ia < n_after; ++ia)
	       B[(ib * n + n - 1) * n_after + ia] = A[ib * n * n_after + ia];
     }
}

/* A = alpha * B  (out of place) */
void rarray_scale(fftw_real *A, fftw_real *B, fftw_real alpha, int n)
{
     int i;

     for (i = 0; i < n; ++i) {
	  A[i] = B[i] * alpha;
     }
}

void rarray_compare(fftw_real *A, fftw_real *B, int n)
{
     double d = compute_error(A, 1, B, 1, n);
     if (d > TOLERANCE) {
	  fflush(stdout);
	  fprintf(stderr, "Found relative error %e\n", d);
	  fftw_die("failure in Ergun's verification procedure\n");
     }
}

/*
 * guaranteed out-of-place transform.  Does the necessary
 * copying if the plan is in-place.
 */
static void rfftw_out_of_place(fftw_plan plan, int n,
			      fftw_real *in, fftw_real *out)
{
     if (plan->flags & FFTW_IN_PLACE) {
	  rarray_copy(out, in, n);
	  rfftw(plan, 1, out, 1, n, (fftw_real *)0, 1, n);
     } else {
	  rfftw(plan, 1, in, 1, n, out, 1, n);
     }
}

/*
 * This is a real (as opposed to complex) variation of the FFT tester
 * described in
 *
 * Funda Ergün. Testing multivariate linear functions: Overcoming the
 * generator bottleneck. In Proceedings of the Twenty-Seventh Annual
 * ACM Symposium on the Theory of Computing, pages 407-416, Las Vegas,
 * Nevada, 29 May--1 June 1995.
 */
void test_ergun(int n, fftw_direction dir, fftw_plan plan)
{
     fftw_real *inA, *inB, *inC, *outA, *outB, *outC;
     fftw_real *inA1, *inB1;
     fftw_real *tmp;
     int i;
     int rounds = 20;
     FFTW_TRIG_REAL twopin = FFTW_K2PI / (FFTW_TRIG_REAL) n;

     inA = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     inB = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     inA1 = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     inB1 = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     inC = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     outA = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     outB = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     outC = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));
     tmp = (fftw_real *) fftw_malloc(n * sizeof(fftw_real));

     WHEN_VERBOSE(2,
		  printf("Validating plan, n = %d, dir = %s\n", n,
			 dir == FFTW_REAL_TO_COMPLEX ? 
			 "REAL_TO_COMPLEX" : "COMPLEX_TO_REAL"));

     /* test 1: check linearity */
     for (i = 0; i < rounds; ++i) {
	  fftw_real alpha, beta;
	  alpha = DRAND();
	  beta = DRAND();
	  rfill_random(inA, n);
	  rfill_random(inB, n);
	  rarray_scale(inA1, inA, alpha, n);
	  rarray_scale(inB1, inB, beta, n);
	  rarray_add(inC, inA1, inB1, n);
	  rfftw_out_of_place(plan, n, inA, outA);
	  rfftw_out_of_place(plan, n, inB, outB);
	  rarray_scale(outA, outA, alpha, n);
	  rarray_scale(outB, outB, beta, n);
	  rarray_add(tmp, outA, outB, n);
	  rfftw_out_of_place(plan, n, inC, outC);
	  rarray_compare(outC, tmp, n);
     }

     /* test 2: check that the unit impulse is transformed properly */
     for (i = 0; i < n; ++i) {
	  /* impulse */
	  inA[i] = 0.0;
	  
	  /* transform of the impulse */
	  if (2 * i <= n)
	       outA[i] = 1.0;
	  else
	       outA[i] = 0.0;
     }
     inA[0] = 1.0;

     if (dir == FFTW_REAL_TO_COMPLEX) {
	  for (i = 0; i < rounds; ++i) {
	       rfill_random(inB, n);
	       rarray_sub(inC, inA, inB, n);
	       rfftw_out_of_place(plan, n, inB, outB);
	       rfftw_out_of_place(plan, n, inC, outC);
	       rarray_add(tmp, outB, outC, n);
	       rarray_compare(tmp, outA, n);
	  }
     } else {
	  for (i = 0; i < rounds; ++i) {
	       rfill_random(outB, n);
	       rarray_sub(outC, outA, outB, n);
	       rfftw_out_of_place(plan, n, outB, inB);
	       rfftw_out_of_place(plan, n, outC, inC);
	       rarray_add(tmp, inB, inC, n);
	       rarray_scale(tmp, tmp, 1.0 / ((double) n), n);
	       rarray_compare(tmp, inA, n);
	  }
     }

     /* test 3: check the time-shift property */
     /* the paper performs more tests, but this code should be fine too */
     if (dir == FFTW_REAL_TO_COMPLEX) {
	  for (i = 0; i < rounds; ++i) {
	       int j;

	       rfill_random(inA, n);
	       rarray_rol(inB, inA, n, 1, 1);
	       rfftw_out_of_place(plan, n, inA, outA);
	       rfftw_out_of_place(plan, n, inB, outB);
	       tmp[0] = outB[0];
	       for (j = 1; 2 * j < n; ++j) {
		    FFTW_TRIG_REAL s = dir * FFTW_TRIG_SIN(j * twopin);
		    FFTW_TRIG_REAL c = FFTW_TRIG_COS(j * twopin);
		    tmp[j] = outB[j] * c - outB[n - j] * s;
		    tmp[n - j] = outB[j] * s + outB[n - j] * c;
	       }
	       if (2 * j == n)
		    tmp[j] = -outB[j];

	       rarray_compare(tmp, outA, n);
	  }
     } else {
	  for (i = 0; i < rounds; ++i) {
	       int j;

	       rfill_random(inA, n);
	       inB[0] = inA[0];
	       for (j = 1; 2 * j < n; ++j) {
		    FFTW_TRIG_REAL s = dir * FFTW_TRIG_SIN(j * twopin);
		    FFTW_TRIG_REAL c = FFTW_TRIG_COS(j * twopin);
		    inB[j] = inA[j] * c - inA[n - j] * s;
		    inB[n - j] = inA[j] * s + inA[n - j] * c;
	       }
	       if (2 * j == n)
		    inB[j] = -inA[j];

	       rfftw_out_of_place(plan, n, inA, outA);
	       rfftw_out_of_place(plan, n, inB, outB);	       
	       rarray_rol(tmp, outA, n, 1, 1);
	       rarray_compare(tmp, outB, n);
	  }
     }

     WHEN_VERBOSE(2, printf("Validation done\n"));

     fftw_free(tmp);
     fftw_free(outC);
     fftw_free(outB);
     fftw_free(outA);
     fftw_free(inC);
     fftw_free(inB1);
     fftw_free(inA1);
     fftw_free(inB);
     fftw_free(inA);
}

static void rfftw_plan_hook_function(fftw_plan p)
{
     WHEN_VERBOSE(3, printf("Validating tentative plan\n"));
     WHEN_VERBOSE(3, fftw_print_plan(p));
     test_ergun(p->n, p->dir, p);
}

/*************************************************
 * test initialization
 *************************************************/

void test_init(int *argc, char **argv)
{
}

void test_finish(void)
{
}

extern void (*rfftw_plan_hook)(fftw_plan plan);
void enter_paranoid_mode(void)
{
     rfftw_plan_hook = rfftw_plan_hook_function;
}

int get_option(int argc, char **argv, char *argval, int argval_maxlen)
{
     return default_get_option(argc,argv,argval,argval_maxlen);
}
