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Diffstat (limited to 'test/bench/nbody.c')
| -rw-r--r-- | test/bench/nbody.c | 170 |
1 files changed, 0 insertions, 170 deletions
diff --git a/test/bench/nbody.c b/test/bench/nbody.c deleted file mode 100644 index 3b95b0592..000000000 --- a/test/bench/nbody.c +++ /dev/null @@ -1,170 +0,0 @@ -/* -Redistribution and use in source and binary forms, with or without -modification, are permitted provided that the following conditions are met: - - * Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. - - * Redistributions in binary form must reproduce the above copyright - notice, this list of conditions and the following disclaimer in the - documentation and/or other materials provided with the distribution. - - * Neither the name of "The Computer Language Benchmarks Game" nor the - name of "The Computer Language Shootout Benchmarks" nor the names of - its contributors may be used to endorse or promote products derived - from this software without specific prior written permission. - -THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" -AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE -IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE -ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE -LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR -CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF -SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS -INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN -CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) -ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE -POSSIBILITY OF SUCH DAMAGE. -*/ - -/* - * The Great Computer Language Shootout - * http://shootout.alioth.debian.org/ - * - * contributed by Christoph Bauer - * - */ - -#include <math.h> -#include <stdio.h> -#include <stdlib.h> - -#define pi 3.141592653589793 -#define solar_mass (4 * pi * pi) -#define days_per_year 365.24 - -struct planet { - double x, y, z; - double vx, vy, vz; - double mass; -}; - -void advance(int nbodies, struct planet * bodies, double dt) -{ - int i, j; - - for (i = 0; i < nbodies; i++) { - struct planet * b = &(bodies[i]); - for (j = i + 1; j < nbodies; j++) { - struct planet * b2 = &(bodies[j]); - double dx = b->x - b2->x; - double dy = b->y - b2->y; - double dz = b->z - b2->z; - double distance = sqrt(dx * dx + dy * dy + dz * dz); - double mag = dt / (distance * distance * distance); - b->vx -= dx * b2->mass * mag; - b->vy -= dy * b2->mass * mag; - b->vz -= dz * b2->mass * mag; - b2->vx += dx * b->mass * mag; - b2->vy += dy * b->mass * mag; - b2->vz += dz * b->mass * mag; - } - } - for (i = 0; i < nbodies; i++) { - struct planet * b = &(bodies[i]); - b->x += dt * b->vx; - b->y += dt * b->vy; - b->z += dt * b->vz; - } -} - -double energy(int nbodies, struct planet * bodies) -{ - double e; - int i, j; - - e = 0.0; - for (i = 0; i < nbodies; i++) { - struct planet * b = &(bodies[i]); - e += 0.5 * b->mass * (b->vx * b->vx + b->vy * b->vy + b->vz * b->vz); - for (j = i + 1; j < nbodies; j++) { - struct planet * b2 = &(bodies[j]); - double dx = b->x - b2->x; - double dy = b->y - b2->y; - double dz = b->z - b2->z; - double distance = sqrt(dx * dx + dy * dy + dz * dz); - e -= (b->mass * b2->mass) / distance; - } - } - return e; -} - -void offset_momentum(int nbodies, struct planet * bodies) -{ - double px = 0.0, py = 0.0, pz = 0.0; - int i; - for (i = 0; i < nbodies; i++) { - px += bodies[i].vx * bodies[i].mass; - py += bodies[i].vy * bodies[i].mass; - pz += bodies[i].vz * bodies[i].mass; - } - bodies[0].vx = - px / solar_mass; - bodies[0].vy = - py / solar_mass; - bodies[0].vz = - pz / solar_mass; -} - -#define NBODIES 5 -struct planet bodies[NBODIES] = { - { /* sun */ - 0, 0, 0, 0, 0, 0, solar_mass - }, - { /* jupiter */ - 4.84143144246472090e+00, - -1.16032004402742839e+00, - -1.03622044471123109e-01, - 1.66007664274403694e-03 * days_per_year, - 7.69901118419740425e-03 * days_per_year, - -6.90460016972063023e-05 * days_per_year, - 9.54791938424326609e-04 * solar_mass - }, - { /* saturn */ - 8.34336671824457987e+00, - 4.12479856412430479e+00, - -4.03523417114321381e-01, - -2.76742510726862411e-03 * days_per_year, - 4.99852801234917238e-03 * days_per_year, - 2.30417297573763929e-05 * days_per_year, - 2.85885980666130812e-04 * solar_mass - }, - { /* uranus */ - 1.28943695621391310e+01, - -1.51111514016986312e+01, - -2.23307578892655734e-01, - 2.96460137564761618e-03 * days_per_year, - 2.37847173959480950e-03 * days_per_year, - -2.96589568540237556e-05 * days_per_year, - 4.36624404335156298e-05 * solar_mass - }, - { /* neptune */ - 1.53796971148509165e+01, - -2.59193146099879641e+01, - 1.79258772950371181e-01, - 2.68067772490389322e-03 * days_per_year, - 1.62824170038242295e-03 * days_per_year, - -9.51592254519715870e-05 * days_per_year, - 5.15138902046611451e-05 * solar_mass - } -}; - -int main(int argc, char ** argv) -{ - int n = atoi(argv[1]); - int i; - - offset_momentum(NBODIES, bodies); - printf ("%.9f\n", energy(NBODIES, bodies)); - for (i = 1; i <= n; i++) - advance(NBODIES, bodies, 0.01); - printf ("%.9f\n", energy(NBODIES, bodies)); - return 0; -} |