Renamed the testPotential to testPotentialSelf

.gitignore

@@ -105,7 +105,7 @@ tests/testDump
 tests/testLogger
 tests/benchmarkInteractions
 tests/testGravityDerivatives
-tests/testPotential
+tests/testPotentialSelf
 
 theory/latex/swift.pdf
 theory/SPH/Kernels/kernels.pdf

tests/Makefile.am

@@ -26,7 +26,7 @@ TESTS = testGreetings testMaths testReading.sh testSingle testKernel testSymmetr
         testAdiabaticIndex testRiemannExact testRiemannTRRS testRiemannHLLC \
         testMatrixInversion testThreadpool testDump testLogger testInteractions.sh \
         testVoronoi1D testVoronoi2D testVoronoi3D testGravityDerivatives \
-	testPeriodicBC.sh testPeriodicBCPerturbed.sh testPotential 
+	testPeriodicBC.sh testPeriodicBCPerturbed.sh testPotentialSelf
 
 # List of test programs to compile
 check_PROGRAMS = testGreetings testReading testSingle testTimeIntegration \
@@ -36,7 +36,7 @@ check_PROGRAMS = testGreetings testReading testSingle testTimeIntegration \
                  testAdiabaticIndex testRiemannExact testRiemannTRRS \
                  testRiemannHLLC testMatrixInversion testDump testLogger \
 		 testVoronoi1D testVoronoi2D testVoronoi3D testPeriodicBC \
-		 testGravityDerivatives testPotential
+		 testGravityDerivatives testPotentialSelf
 
 # Rebuild tests when SWIFT is updated.
 $(check_PROGRAMS): ../src/.libs/libswiftsim.a
@@ -100,7 +100,7 @@ testLogger_SOURCES = testLogger.c
 
 testGravityDerivatives_SOURCES = testGravityDerivatives.c
 
-testPotential_SOURCES = testPotential.c
+testPotentialSelf_SOURCES = testPotentialSelf.c
 
 # Files necessary for distribution
 EXTRA_DIST = testReading.sh makeInput.py testActivePair.sh \

tests/testPotentialSelf.c

+/*******************************************************************************
+ * This file is part of SWIFT.
+ * Copyright (C) 2015 Matthieu Schaller (matthieu.schaller@durham.ac.uk).
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 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 Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
+#include "../config.h"
+
+/* Some standard headers. */
+#include <fenv.h>
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+/* Local headers. */
+#include "runner_doiact_grav.h"
+#include "swift.h"
+
+const int num_tests = 100;
+const double eps = 0.02;
+
+/**
+ * @brief Check that a and b are consistent (up to some relative error)
+ *
+ * @param a First value
+ * @param b Second value
+ * @param s String used to identify this check in messages
+ */
+void check_value(double a, double b, const char *s) {
+  if (fabs(a - b) / fabs(a + b) > 2e-6 && fabs(a - b) > 1.e-6)
+    error("Values are inconsistent: %12.15e %12.15e (%s)!", a, b, s);
+}
+
+/* Definitions of the potential and force that match
+   exactly the theory document */
+double S(double x) { return exp(x) / (1. + exp(x)); }
+
+double S_prime(double x) { return exp(x) / ((1. + exp(x)) * (1. + exp(x))); }
+
+double potential(double mass, double r, double H, double rlr) {
+
+  const double u = r / H;
+  const double x = r / rlr;
+  double pot;
+  if (u > 1.)
+    pot = -mass / r;
+  else
+    pot = -mass *
+          (-3. * u * u * u * u * u * u * u + 15. * u * u * u * u * u * u -
+           28. * u * u * u * u * u + 21. * u * u * u * u - 7. * u * u + 3.) /
+          H;
+
+  return pot * (2. - 2. * S(2. * x));
+}
+
+double acceleration(double mass, double r, double H, double rlr) {
+
+  const double u = r / H;
+  const double x = r / rlr;
+  double acc;
+  if (u > 1.)
+    acc = -mass / (r * r * r);
+  else
+    acc = -mass * (21. * u * u * u * u * u - 90. * u * u * u * u +
+                   140. * u * u * u - 84. * u * u + 14.) /
+          (H * H * H);
+
+  return r * acc * (4. * x * S_prime(2 * x) - 2. * S(2. * x) + 2.);
+}
+
+int main() {
+
+  /* Initialize CPU frequency, this also starts time. */
+  unsigned long long cpufreq = 0;
+  clocks_set_cpufreq(cpufreq);
+
+  /* Initialise a few things to get us going */
+  struct engine e;
+  e.max_active_bin = num_time_bins;
+  e.time = 0.1f;
+  e.ti_current = 8;
+  e.time_base = 1e-10;
+
+  struct space s;
+  s.width[0] = 0.2;
+  s.width[1] = 0.2;
+  s.width[2] = 0.2;
+  e.s = &s;
+
+  struct gravity_props props;
+  props.a_smooth = 1.25;
+  e.gravity_properties = &props;
+
+  struct runner r;
+  bzero(&r, sizeof(struct runner));
+  r.e = &e;
+
+  const double rlr = props.a_smooth * s.width[0];
+
+  /* Init the cache for gravity interaction */
+  gravity_cache_init(&r.ci_gravity_cache, num_tests * 2);
+
+  /* Let's create one cell with a massive particle and a bunch of test particles
+   */
+  struct cell c;
+  bzero(&c, sizeof(struct cell));
+  c.width[0] = 1.;
+  c.width[1] = 1.;
+  c.width[2] = 1.;
+  c.loc[0] = 0.;
+  c.loc[1] = 0.;
+  c.loc[2] = 0.;
+  c.gcount = 1 + num_tests;
+  c.ti_old_gpart = 8;
+  c.ti_gravity_end_min = 8;
+  c.ti_gravity_end_max = 8;
+
+  posix_memalign((void **)&c.gparts, gpart_align,
+                 c.gcount * sizeof(struct gpart));
+  bzero(c.gparts, c.gcount * sizeof(struct gpart));
+
+  /* Create the massive particle */
+  c.gparts[0].x[0] = 0.;
+  c.gparts[0].x[1] = 0.5;
+  c.gparts[0].x[2] = 0.5;
+  c.gparts[0].mass = 1.;
+  c.gparts[0].epsilon = eps;
+  c.gparts[0].time_bin = 1;
+  c.gparts[0].type = swift_type_dark_matter;
+  c.gparts[0].id_or_neg_offset = 1;
+#ifdef SWIFT_DEBUG_CHECKS
+  c.gparts[0].ti_drift = 8;
+#endif
+
+  /* Create the mass-less particles */
+  for (int n = 1; n < num_tests + 1; ++n) {
+
+    struct gpart *gp = &c.gparts[n];
+
+    gp->x[0] = n / ((double)num_tests);
+    gp->x[1] = 0.5;
+    gp->x[2] = 0.5;
+    gp->mass = 0.;
+    gp->epsilon = eps;
+    gp->time_bin = 1;
+    gp->type = swift_type_dark_matter;
+    gp->id_or_neg_offset = n + 1;
+#ifdef SWIFT_DEBUG_CHECKS
+    gp->ti_drift = 8;
+#endif
+  }
+
+  /* Now compute the forces */
+  runner_doself_grav_pp_truncated(&r, &c);
+
+  /* Verify everything */
+  for (int n = 1; n < num_tests + 1; ++n) {
+    const struct gpart *gp = &c.gparts[n];
+
+    double pot_true = potential(c.gparts[0].mass, gp->x[0], gp->epsilon, rlr);
+    double acc_true =
+        acceleration(c.gparts[0].mass, gp->x[0], gp->epsilon, rlr);
+
+    // message("x=%e f=%e f_true=%e", gp->x[0], gp->a_grav[0], acc_true);
+
+    check_value(gp->potential, pot_true, "potential");
+    check_value(gp->a_grav[0], acc_true, "acceleration");
+  }
+
+  free(c.gparts);
+  return 0;
+}