From 0b79dd32a4ada026a404de18004675fc3765408f Mon Sep 17 00:00:00 2001
From: Orestis <orestis.malaspinas@hesge.ch>
Date: Wed, 26 Aug 2020 22:11:59 +0200
Subject: [PATCH] updated for friction
---
practical_work/forces/Makefile | 10 ++++++++--
practical_work/forces/main.c | 16 +++++++++++++++-
practical_work/forces/particle.c | 28 +++++++++++++---------------
practical_work/forces/particle.h | 6 ++++--
practical_work/vec2/Makefile | 5 ++++-
practical_work/vec2/vec2.c | 10 ++++++++++
practical_work/vec2/vec2.h | 2 ++
7 files changed, 56 insertions(+), 21 deletions(-)
diff --git a/practical_work/forces/Makefile b/practical_work/forces/Makefile
index 111de51..b850094 100644
--- a/practical_work/forces/Makefile
+++ b/practical_work/forces/Makefile
@@ -1,8 +1,9 @@
CC=gcc
-OPTS=-g -O3 -Wall -Wextra -fsanitize=address -fsanitize=leak
+OPTS=-g -O3 -Wall -Wextra -fsanitize=address -fsanitize=leak -std=c11
LINK=-lm -lasan
-main: main.o particle.o ../vec2/vec2.o
+main: main.o particle.o ../vec2/util.o ../vec2/vec2.o
+ make -C ../vec2
$(CC) $(OPTS) -o $@ $^ $(LINK)
main.o: main.c
@@ -11,5 +12,10 @@ main.o: main.c
particle.o: particle.c particle.h
$(CC) $(OPTS) -c $^
+util.o: util.c util.h
+ $(CC) $(OPTS) -c $^
+
clean:
rm -f *.o main
+ make -C ../vec2 clean
+
diff --git a/practical_work/forces/main.c b/practical_work/forces/main.c
index b29a965..762024f 100644
--- a/practical_work/forces/main.c
+++ b/practical_work/forces/main.c
@@ -8,7 +8,7 @@ int main() {
particle_print(p);
int number = 10;
- particle *parts = particle_random_create_list(vec2_create(0.0,0.0), vec2_create(1.0, 1.0), 0.0, 10.0, number);
+ particle *parts = particle_create_random_list(vec2_create(0.0,0.0), vec2_create(1.0, 1.0), 0.0, 10.0, number);
particle_print_list(parts, number);
vec2 force = particle_compute_grav_force(parts[0], p);
@@ -20,5 +20,19 @@ int main() {
vec2_print(forces[ip]);
}
+ double k = 10.0;
+ vec2 vel[number];
+ for (int ip = 0; ip < number; ++ip) {
+ vel[ip] = vec2_create_random(vec2_create(0.0,0.0), vec2_create(1.0, 1.0));
+ }
+ vec2 *forces_friction = particle_compute_grav_friction_resultant_forces(parts, vel, k, number);
+
+ for (int ip = 0; ip < number; ++ip) {
+ printf("force %d: \n", ip);
+ vec2_print(forces_friction[ip]);
+ }
+
free(parts);
+ free(forces);
+ free(forces_friction);
}
\ No newline at end of file
diff --git a/practical_work/forces/particle.c b/practical_work/forces/particle.c
index e7a5c5e..8f5fbad 100644
--- a/practical_work/forces/particle.c
+++ b/practical_work/forces/particle.c
@@ -3,39 +3,29 @@
#include <time.h>
#include <assert.h>
#include "particle.h"
+#include "../vec2/util.h"
static double G = 6.27e-11;
-static double rand_to_range(double x0, double x1) {
- double delta = x1 - x0;
- double rescaled = (double)rand() / RAND_MAX * delta + x0;
-
- return rescaled;
-}
-
particle particle_create(vec2 r_, double m_) {
particle p = {.r = r_, .m = m_};
return p;
}
-particle particle_random_create(vec2 min_r, vec2 max_r, double min_m, double max_m) {
+particle particle_create_random(vec2 min_r, vec2 max_r, double min_m, double max_m) {
double m = rand_to_range(min_m, max_m);
-
- double x = rand_to_range(min_r.x, max_r.x);
- double y = rand_to_range(min_r.y, max_r.y);
-
- vec2 r = vec2_create(x, y);
+ vec2 r = vec2_create_random(min_r, max_r);
return particle_create(r, m);
}
-particle *particle_random_create_list(vec2 min_r, vec2 max_r, double min_m, double max_m, int number) {
+particle *particle_create_random_list(vec2 min_r, vec2 max_r, double min_m, double max_m, int number) {
particle *p = malloc(number * sizeof(particle));
srand(time(NULL));
for (int ip = 0; ip < number; ++ip) {
- p[ip] = particle_random_create(min_r, max_r, min_m, max_m);
+ p[ip] = particle_create_random(min_r, max_r, min_m, max_m);
}
return p;
@@ -64,6 +54,14 @@ vec2 *particle_compute_grav_resultant_forces(particle *parts, int number) {
return forces;
}
+vec2 *particle_compute_grav_friction_resultant_forces(particle *parts, vec2 *vel, double k, int number) {
+ vec2 *forces = particle_compute_grav_resultant_forces(parts, number);
+ for (int ip = 0; ip < number; ++ip) {
+ forces[ip] = vec2_sub(forces[ip], vec2_mul(k, vel[ip]));
+ }
+ return forces;
+}
+
void particle_print(particle p) {
printf("m = %g\n", p.m);
vec2_print(p.r);
diff --git a/practical_work/forces/particle.h b/practical_work/forces/particle.h
index 3e4b66b..5d1eb25 100644
--- a/practical_work/forces/particle.h
+++ b/practical_work/forces/particle.h
@@ -10,14 +10,16 @@ typedef struct _particle {
particle particle_create(vec2 r_, double m_);
-particle particle_random_create(vec2 min_r, vec2 max_r, double min_m, double max_m);
+particle particle_create_random(vec2 min_r, vec2 max_r, double min_m, double max_m);
-particle *particle_random_create_list(vec2 min_r, vec2 max_r, double min_m, double max_m, int number);
+particle *particle_create_random_list(vec2 min_r, vec2 max_r, double min_m, double max_m, int number);
vec2 particle_compute_grav_force(particle lhs, particle rhs);
vec2 *particle_compute_grav_resultant_forces(particle *parts, int number);
+vec2 *particle_compute_grav_friction_resultant_forces(particle *parts, vec2 *vel, double k, int number);
+
void particle_print(particle p);
void particle_print_list(particle *p, int number);
diff --git a/practical_work/vec2/Makefile b/practical_work/vec2/Makefile
index 79d77da..08e9c73 100644
--- a/practical_work/vec2/Makefile
+++ b/practical_work/vec2/Makefile
@@ -2,7 +2,7 @@ CC=gcc
OPTS=-g -O3 -Wall -Wextra
LINK=-lm
-main: main.o vec2.o
+main: main.o vec2.o util.o
$(CC) $(OPTS) -o $@ $^ $(LINK)
main.o: main.c
@@ -11,6 +11,9 @@ main.o: main.c
vec2.o: vec2.c vec2.h
$(CC) $(OPTS) -c $^
+util.o: util.c util.h
+ $(CC) $(OPTS) -c $^
+
test:
make -C tests test
diff --git a/practical_work/vec2/vec2.c b/practical_work/vec2/vec2.c
index abae499..a221bb8 100644
--- a/practical_work/vec2/vec2.c
+++ b/practical_work/vec2/vec2.c
@@ -1,5 +1,6 @@
#include <stdio.h>
#include <math.h>
+#include "util.h"
#include "vec2.h"
vec2 vec2_create(double x_, double y_) {
@@ -11,6 +12,15 @@ vec2 vec2_create_zero() {
return vec2_create(0.0, 0.0);
}
+vec2 vec2_create_random(vec2 min_r, vec2 max_r) {
+ double x = rand_to_range(min_r.x, max_r.x);
+ double y = rand_to_range(min_r.y, max_r.y);
+
+ vec2 r = vec2_create(x, y);
+
+ return r;
+}
+
vec2 vec2_add(vec2 lhs, vec2 rhs) {
return vec2_create(
lhs.x + rhs.x,
diff --git a/practical_work/vec2/vec2.h b/practical_work/vec2/vec2.h
index 3d4dc15..80704b1 100644
--- a/practical_work/vec2/vec2.h
+++ b/practical_work/vec2/vec2.h
@@ -9,6 +9,8 @@ typedef struct _vec2 {
vec2 vec2_create(double x_, double y_);
+vec2 vec2_create_random(vec2 min_v, vec2 max_v);
+
vec2 vec2_create_zero();
vec2 vec2_add(vec2 lhs, vec2 rhs);
--
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