aboutsummaryrefslogtreecommitdiff
path: root/src/patch/test_patch_system.cc
blob: 82df69e23d15e8889c35e62c13b5e9ebc027dabf (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
// test_patch_system.cc -- test driver for patch_system::
// $Id$

//
// <<<misc global data>>>
// <<<prototypes>>>
//
// driver - Cactus interface
//
/// setup_sym_fn_xyz - set up symmetrized test function fn(global_[xyz])
/// setup_fn_rho_sigma - set up test function fn(rho,sigma)
/// finite_diff - compute linear combination of finite differences
/// analytic_derivs - compute linear combination of analytic derivatives
///
/// sym_fn_xyz - symmetrized test function fn(x,y,z) + fn(-y,x,z) + ...
/// fn_xyz - test function fn(x,y,z)
///
/// gridfn_minus - compute gridfn x - gridfn y --> gridfn z
/// ghosted_gridfn_minus - compute [ghosted] gridfn x - gridfn y --> gridfn z
///
/// fn_rho_sigma - test function fn(rho,sigma)
/// finite_diff_fn - finite differences of fn(rho,sigma)
/// analytic_deriv_fn - analytical derivs of fn(rho,sigma) (via Maple)
//

#include <stdio.h>
#include <assert.h>
#include <math.h>
#include <vector>

#include "util_Table.h"
#include "cctk.h"
#include "cctk_Arguments.h"
#include "cctk_Parameters.h"

#include "jt/stdc.h"
#include "jt/util.hh"
#include "jt/array.hh"
#include "jt/cpm_map.hh"
#include "jt/linear_map.hh"
using jtutil::error_exit;

#include "fp.hh"
#include "coords.hh"
#include "grid.hh"
#include "fd_grid.hh"
#include "patch.hh"
#include "patch_edge.hh"
#include "ghost_zone.hh"
#include "patch_frontier.hh"
#include "patch_system.hh"

//******************************************************************************

//
// misc global data
//

// which test are we going to do?
static const int which_deriv_fn          = 0x1;
static const int which_deriv_rho         = 0x2;
static const int which_deriv_sigma       = 0x4;
static const int which_deriv_rho_rho     = 0x8;
static const int which_deriv_rho_sigma   = 0x10;
static const int which_deriv_sigma_sigma = 0x20;

// when testing multiple derivatives, we combine them together
// with these "quasi-random" weights (chosen from digits of pi)
static const fp deriv_weight_fn          = 3.14,
		deriv_weight_rho         = 1.59,
		deriv_weight_sigma       = 2.65,
		deriv_weight_rho_rho     = 3.58,
		deriv_weight_rho_sigma   = 9.79,
		deriv_weight_sigma_sigma = 3.23;

// nominal gridfns
static const int FD_derivs_gfn = -1;
static const int analytic_derivs_gfn = -2;
static const int nominal_error_gfn = -3;
static const int nominal_min_gfn = -3;
static const int nominal_max_gfn = -1;

// ghosted gridfns
static const int test_fn_gfn = 1;
static const int test_fn_copy_gfn = 2;
static const int ghosted_error_gfn = 3;
static const int ghosted_min_gfn = 1;
static const int ghosted_max_gfn = 3;

//******************************************************************************

//
// ***** prototypes *****
//

extern "C"
  void test_patch_system(CCTK_ARGUMENTS);

namespace {
void setup_sym_fn_xyz(patch_system& ps, int ghosted_gfn, bool want_ghost_zones);
void setup_fn_rho_sigma(patch_system& ps, int ghosted_gfn);
void finite_diff(patch_system& ps,
		 int ghosted_gfn_src, int gfn_dst,
		 int which_derivs);
void analytic_derivs(patch_system& ps, int gfn_dst, int which_derivs);
void gridfn_minus(patch_system& ps, 
		  int gfn_x, int gfn_y, int gfn_dst);
void ghosted_gridfn_minus(patch_system& ps, 
			  int ghosted_gfn_x, int ghosted_gfn_y,
			  int ghosted_gfn_dst);

fp sym_fn_xyz(enum patch_system::patch_system_type type, fp x, fp y, fp z);
fp fn_xyz(fp x, fp y, fp z);

fp fn_rho_sigma(fp rho, fp sigma);
fp finite_diff_fn(const patch& p,
		  int ghosted_gfn_src, int which_derivs,
		  int irho, int isigma);
fp analytic_deriv_fn(fp rho, fp sigma, int which_derivs);
	  };

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This function is the Cactus interface for the test driver.
//
extern "C"
  void test_patch_system(CCTK_ARGUMENTS)
{
DECLARE_CCTK_ARGUMENTS
DECLARE_CCTK_PARAMETERS

//
// set up the interpatch interpolator
//
CCTK_VInfo(CCTK_THORNSTRING, "setting up interpatch interpolator");
const int interp_handle = CCTK_InterpHandle(interpatch_interpolator_name);
if (interp_handle < 0)
   then CCTK_VWarn(-1, __LINE__, __FILE__, CCTK_THORNSTRING,
		   "couldn't find interpolator \"%s\"!",
		   interpatch_interpolator_name);		/*NOTREACHED*/
const int interp_par_table_handle
	= Util_TableCreateFromString(interpatch_interpolator_pars);
if (interp_par_table_handle < 0)
   then CCTK_VWarn(-1, __LINE__, __FILE__, CCTK_THORNSTRING,
		   "bad interpatch-interpolator parameter(s) \"%s\"!",
		   interpatch_interpolator_pars);		/*NOTREACHED*/

//
// create the patch system
//
CCTK_VInfo(CCTK_THORNSTRING, "about to create patch system");
patch_system ps(origin_x, origin_y, origin_z,
		patch_system::type_of_name(patch_system_type),
		N_ghost_points, N_overlap_points, delta_drho_dsigma,
		nominal_min_gfn, nominal_max_gfn,
		ghosted_min_gfn, ghosted_max_gfn,
		interp_handle, interp_par_table_handle);
CCTK_VInfo(CCTK_THORNSTRING, "patch system created ok");

//
// do the actual tests
//
FILE *output_file_ptr = fopen(output_file_name, "w");
if (output_file_ptr == NULL)
   then CCTK_VWarn(-1, __LINE__, __FILE__, CCTK_THORNSTRING,
		   "can't open output file \"%s\"!",
		   output_file_name);				/*NOTREACHED*/
if      (STRING_EQUAL(which_test, "gridfn"))
   then {
	setup_sym_fn_xyz(ps, test_fn_gfn, true);
	ps.print_ghosted_gridfn(test_fn_gfn, true, output_file_ptr);
	}
else if (STRING_EQUAL(which_test, "synchronize"))
   then {
	setup_sym_fn_xyz(ps, test_fn_gfn, false);
	setup_sym_fn_xyz(ps, test_fn_copy_gfn, true);
	ps.synchronize_ghost_zones(test_fn_gfn, test_fn_gfn);
	ghosted_gridfn_minus(ps,
			     test_fn_gfn, test_fn_copy_gfn,
			     ghosted_error_gfn);
	ps.print_ghosted_gridfn(ghosted_error_gfn, true, output_file_ptr);
	}
else if (STRING_EQUAL(which_test, "derivatives"))
   then {
	setup_fn_rho_sigma(ps, test_fn_gfn);
	finite_diff(ps, test_fn_gfn, FD_derivs_gfn, which_derivs);
	analytic_derivs(ps, analytic_derivs_gfn, which_derivs);
	gridfn_minus(ps,
		     FD_derivs_gfn, analytic_derivs_gfn,
		     nominal_error_gfn);
	ps.print_gridfn(nominal_error_gfn, output_file_ptr);
	}
else	CCTK_VWarn(-1, __LINE__, __FILE__, CCTK_THORNSTRING,
		   "unknown which_test=\"%s\"!",
		   which_test);					/*NOTREACHED*/
fclose(output_file_ptr);

CCTK_VInfo(CCTK_THORNSTRING, "destroying patch system");
}

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This function sets up the ghosted test function for the gridfn and
// synchronize tests, symmetrizing the test function to match the
// symmetry of the patch system.
//
// Arguments:
// ps = The patch system.
// ghosted_gfn = Specifies the gridfn to set up.
// want_ghost_zones = true ==> Set up on ghosted part of ghosted grid
//		      false ==> Set up on nominal part of ghosted grid
//
namespace {
void setup_sym_fn_xyz(patch_system& ps, int ghosted_gfn, bool want_ghost_zones)
{
CCTK_VInfo(CCTK_THORNSTRING, "setting up ghosted test fn(x,y,z)");
CCTK_VInfo(CCTK_THORNSTRING, "   on %s part of ghosted grid",
	   want_ghost_zones ? "ghosted" : "nominal");

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

		for (int irho = p.effective_min_irho(want_ghost_zones) ;
		     irho <= p.effective_max_irho(want_ghost_zones) ;
		     ++irho)
		{
		for (int isigma = p.effective_min_isigma(want_ghost_zones) ;
		     isigma <= p.effective_max_isigma(want_ghost_zones) ;
		     ++isigma)
		{
		const fp rho = p.rho_of_irho(irho);
		const fp sigma = p.sigma_of_isigma(isigma);

		fp local_x, local_y, local_z;
		p.xyz_of_r_rho_sigma(1.0, rho, sigma,
				     local_x, local_y, local_z);

		p.ghosted_gridfn(ghosted_gfn, irho,isigma)
			= sym_fn_xyz(ps.type(), local_x, local_y, local_z);
		}
		}
	}
}
	  }

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This function sets up the test function for the finite differencing
// tests.
//
// Arguments:
// ps = The patch system.
// ghosted_gfn = Specifies the gridfn to set up.
//
namespace {
void setup_fn_rho_sigma(patch_system& ps, int ghosted_gfn)
{
CCTK_VInfo(CCTK_THORNSTRING, "setting up ghosted test fn(rho,sigma)");

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

		for (int irho = p.ghosted_min_irho() ;
		     irho <= p.ghosted_max_irho() ;
		     ++irho)
		{
		for (int isigma = p.ghosted_min_isigma() ;
		     isigma <= p.ghosted_max_isigma() ;
		     ++isigma)
		{
		const fp rho = p.rho_of_irho(irho);
		const fp sigma = p.sigma_of_isigma(isigma);

		p.ghosted_gridfn(ghosted_gfn, irho,isigma)
			= fn_rho_sigma(rho, sigma);
		}
		}
	}
}
	  }

//******************************************************************************

//
// This function computes (on the nominal grid only) the specified
// linear combination of finite derivatives of a test function.
//
// Arguments:
// ps = The patch system.
// gfn_src = Specifies the gridfn to finite difference.
// gfn_dst = Specifies the gridfn in which to store the result.
// which = Specifies which finite derivatives to include in the test.
//
namespace {
void finite_diff(patch_system& ps,
		 int ghosted_gfn_src, int gfn_dst,
		 int which_derivs)
{
CCTK_VInfo(CCTK_THORNSTRING,
	   "finite differencing ghosted_gfn=%d --> gfn=%d (which_derivs=%d)",
	   ghosted_gfn_src, gfn_dst, which_derivs);

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

	for (int irho = p.min_irho() ; irho <= p.max_irho() ; ++irho)
	{
	for (int isigma = p.min_isigma() ; isigma <= p.max_isigma() ; ++isigma)
	{
	p.gridfn(gfn_dst, irho,isigma)
		= finite_diff_fn(p,
				 ghosted_gfn_src, which_derivs,
				 irho,isigma);
	}
	}

	}
}
	  }

//******************************************************************************

//
// This function computes the specified linear combination of
// derivatives of the test function, everywhere on the nominal grid.
//
namespace {
void analytic_derivs(patch_system& ps,
		     int gfn_dst,
		     int which_derivs)
{
CCTK_VInfo(CCTK_THORNSTRING,
	   "computing analytic derivatives (which_derivs=%d)",
	   which_derivs);

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

	for (int irho = p.min_irho() ; irho <= p.max_irho() ; ++irho)
	{
	for (int isigma = p.min_isigma() ; isigma <= p.max_isigma() ; ++isigma)
	{
	const fp rho = p.rho_of_irho(irho);
	const fp sigma = p.sigma_of_isigma(isigma);
	p.gridfn(gfn_dst, irho,isigma)
		= analytic_deriv_fn(rho,sigma, which_derivs);
	}
	}

	}
}
	  }

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This function computes [nominal]  gridfn_x - gridfn_y --> gridfn_z .
//
namespace {
void gridfn_minus(patch_system& ps, 
		  int gfn_x, int gfn_y, int gfn_dst)
{
CCTK_VInfo(CCTK_THORNSTRING,
	   "[nominal] gfn=%d - gfn=%d --> gfn=%d",
	   gfn_x, gfn_y, gfn_dst);

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

	for (int irho = p.min_irho() ; irho <= p.max_irho() ; ++irho)
	{
	for (int isigma = p.min_isigma() ; isigma <= p.max_isigma() ; ++isigma)
	{
	p.gridfn(gfn_dst, irho,isigma)
		=   p.gridfn(gfn_x, irho,isigma)
		  - p.gridfn(gfn_y, irho,isigma);
	}
	}

	}
}
	  }

//******************************************************************************

//
// This function computes [ghosted]  gridfn_x - gridfn_y --> gridfn_z .
//
namespace {
void ghosted_gridfn_minus(patch_system& ps, 
			  int ghosted_gfn_x, int ghosted_gfn_y,
			  int ghosted_gfn_dst)
{
CCTK_VInfo(CCTK_THORNSTRING,
	   "[ghosted] gfn=%d - gfn=%d --> gfn=%d",
	   ghosted_gfn_x, ghosted_gfn_y, ghosted_gfn_dst);

	for (int pn = 0 ; pn < ps.N_patches() ; ++pn)
	{
	patch& p = ps.ith_patch(pn);

		for (int irho = p.ghosted_min_irho() ;
		     irho <= p.ghosted_max_irho() ;
		     ++irho)
		{
		for (int isigma = p.ghosted_min_isigma() ;
		     isigma <= p.ghosted_max_isigma() ;
		     ++isigma)
		{
		p.ghosted_gridfn(ghosted_gfn_dst, irho,isigma)
			=   p.ghosted_gridfn(ghosted_gfn_x, irho,isigma)
			  - p.ghosted_gridfn(ghosted_gfn_y, irho,isigma);
		}
		}

	}
}
	  }

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This function symmetrizes  fn_xyz()  (about the origin) to match
// the patch system's symmetries.
//
// To rotate f(x,y) by 90, 180, or 270 degrees:
//
//	      (-y,x) |
//	             |
//	             |
//	             |
//	             |        (x,y)
//	             |
//	-------------+-------------
//	             |
//	(-x,-y)      |
//	             |
//	             |
//	             |
//	             | (y,-x)
//
namespace {
fp sym_fn_xyz(enum patch_system::patch_system_type type, fp x, fp y, fp z)
{
switch	(type)
	{
case patch_system::full_sphere_patch_system:
	return fn_xyz(x,y,z);
	break;
case patch_system::plus_z_hemisphere_patch_system:
	return fn_xyz(x,y,+z) + fn_xyz(x,y,-z);
	break;
case patch_system::plus_xy_quadrant_patch_system:
	return   fn_xyz(+x,+y,z)
	       + fn_xyz(-y,+x,z)
	       + fn_xyz(-x,-y,z)
	       + fn_xyz(+y,-x,z);
	break;
case patch_system::plus_xz_quadrant_patch_system:
	return   fn_xyz(+x,+y,+z) + fn_xyz(-x,-y,+z)
	       + fn_xyz(+x,+y,-z) + fn_xyz(-x,-y,-z);
	break;
case patch_system::plus_xyz_octant_patch_system:
	return   fn_xyz(+x,+y,+z) + fn_xyz(+x,+y,-z)
	       + fn_xyz(-y,+x,+z) + fn_xyz(-y,+x,-z)
	       + fn_xyz(-x,-y,+z) + fn_xyz(-x,-y,-z)
	       + fn_xyz(+y,-x,+z) + fn_xyz(+y,-x,-z);
	break;
default:
	error_exit(PANIC_EXIT,
"***** sym_fn_xyz(): impossible type=(int)%d!\n",
		   int(type));					/*NOTREACHED*/
			}
}
	  };

//******************************************************************************

//
// This is the underlying test function for our function and ghost-zone tests.
//
namespace {
fp fn_xyz(fp x, fp y, fp z)
{
return (x*(x+0.238) + 2.417*y*(y-0.917) + 1.38*z*(z-0.472))
       * tanh(jtutil::pow3(cos(z)));
}
	  };

//******************************************************************************
//******************************************************************************
//******************************************************************************

//
// This is the underlying test function for our finite differencing
// tests.
//
namespace {
fp fn_rho_sigma(fp rho, fp sigma)
{
return exp(sin(1.38*rho)) * tanh(0.17+0.83*jtutil::pow2(sin(sigma)));
}
	  };

//******************************************************************************

//
// This function computes the sum of our linear combination of various
// finite difference approximations to derivatives of fn_rho_sigma().
//
// Arguments:
// ghosted_gfn_src = Specifies the gridfn to finite difference.
//
namespace {
fp finite_diff_fn(const patch& p,
		  int ghosted_gfn_src, int which_derivs,
		  int irho, int isigma)
{
fp sum = 0.0;

if (which_derivs & which_deriv_fn)
   then sum += deriv_weight_fn
	       * p.ghosted_gridfn(ghosted_gfn_src, irho,isigma);

if (which_derivs & which_deriv_rho)
   then sum += deriv_weight_rho
	       * p.partial_rho(ghosted_gfn_src, irho,isigma);
if (which_derivs & which_deriv_sigma)
   then sum += deriv_weight_sigma
	       * p.partial_sigma(ghosted_gfn_src, irho,isigma);

if (which_derivs & which_deriv_rho_rho)
   then sum += deriv_weight_rho_rho
	       * p.partial_rho_rho(ghosted_gfn_src, irho,isigma);
if (which_derivs & which_deriv_rho_sigma)
   then sum += deriv_weight_rho_sigma
	       * p.partial_rho_sigma(ghosted_gfn_src, irho,isigma);
if (which_derivs & which_deriv_sigma_sigma)
   then sum += deriv_weight_sigma_sigma
	       * p.partial_sigma_sigma(ghosted_gfn_src, irho,isigma);

return sum;
}
	  };

//******************************************************************************

//
// This function computes the sum of a specified linear combination of
// various (analytical) derivatives of fn_rho_sigma().
//
// The derivatives were machine-generated via Maple's codegen[C]() function:
// "deriv_patch_system.maple" is the Maple input
// "deriv_patch_system.out" is the Maple input; code here is cut-n-pasted
//			   from the Maple codegen[C]() output there
//
namespace {
fp analytic_deriv_fn(fp rho, fp sigma, int which_derivs)
{
fp sum = 0.0;

if (which_derivs & which_deriv_fn)
   then sum += deriv_weight_fn
	       * fn_rho_sigma(rho,sigma);

if (which_derivs & which_deriv_rho)
   then sum += deriv_weight_rho
	       * 0.138E1*cos(0.138E1*rho)*exp(sin(0.138E1*rho))
		 *tanh(0.17+0.83*pow(sin(sigma),2.0));
if (which_derivs & which_deriv_sigma)
   then sum += deriv_weight_sigma
	       * 0.166E1*exp(sin(0.138E1*rho))
		 *(1.0-pow(tanh(0.17+0.83*pow(sin(sigma),2.0)),2.0))
		 *sin(sigma)*cos(sigma);

if (which_derivs & which_deriv_rho_rho)
   then sum += deriv_weight_rho_rho
	       * (
		 -0.19044E1*sin(0.138E1*rho)*exp(sin(0.138E1*rho))
		  *tanh(0.17+0.83*pow(sin(sigma),2.0))
		 +0.19044E1*pow(cos(0.138E1*rho),2.0)*exp(sin(0.138E1*rho))
		  *tanh(0.17+0.83*pow(sin(sigma),2.0))
		 );
if (which_derivs & which_deriv_rho_sigma)
   then sum += deriv_weight_rho_sigma
	       * 0.22908E1*cos(0.138E1*rho)*exp(sin(0.138E1*rho))
		 *(1.0-pow(tanh(0.17+0.83*pow(sin(sigma),2.0)),2.0))
		 *sin(sigma)*cos(sigma);
if (which_derivs & which_deriv_sigma_sigma)
   then sum += deriv_weight_sigma_sigma
	       * (
		 -0.55112E1*exp(sin(0.138E1*rho))
		  *tanh(0.17+0.83*pow(sin(sigma),2.0))
		  *(1.0-pow(tanh(0.17+0.83*pow(sin(sigma),2.0)),2.0))
		  *pow(sin(sigma),2.0)*pow(cos(sigma),2.0)
		 +0.166E1*exp(sin(0.138E1*rho))
		  *(1.0-pow(tanh(0.17+0.83*pow(sin(sigma),2.0)),2.0))
		  *pow(cos(sigma),2.0)
		 -0.166E1*exp(sin(0.138E1*rho))
		  *(1.0-pow(tanh(0.17+0.83*pow(sin(sigma),2.0)),2.0))
		  *pow(sin(sigma),2.0)
		 );

return sum;
}
	  };