From ede77458c98452da90501f3d5ea868529475cdec Mon Sep 17 00:00:00 2001
From: Hugo TRACHINO <hugo.trachino@pc127-01.pedago.ensiie.fr>
Date: Fri, 27 Sep 2019 17:41:32 +0200
Subject: [PATCH] montecarlo computing pi like a boss
---
fcts.h | 3 +--
monte_carlo.cpp | 32 ++++++++++++++++++++++++++++++++
2 files changed, 33 insertions(+), 2 deletions(-)
create mode 100644 monte_carlo.cpp
diff --git a/fcts.h b/fcts.h
index 1b9bcbd..c64354f 100644
--- a/fcts.h
+++ b/fcts.h
@@ -14,7 +14,7 @@ long uniform() {
lo+= (hi & 0x7FFF) << 16;
lo+= hi >> 15;
- if (lo > 0x7FFFFFFFF)
+ if (lo > 0x7FFFFFFF)
lo -= 0x7FFFFFFF;
seed=(long) lo;
return seed ;
@@ -31,7 +31,6 @@ void store_res(long * res, int freqs[], int nRNG, int nCuts){
freqcsv.open("gva_freqs.csv");
int i;
for (i = 0; i < nRNG; i ++){
- printf("i = %d, nRNG= %d\n ", i, nRNG);
freqs[res[i]%nCuts] ++;
myfile << res[i];
myfile << "\n";
diff --git a/monte_carlo.cpp b/monte_carlo.cpp
new file mode 100644
index 0000000..1f6de92
--- /dev/null
+++ b/monte_carlo.cpp
@@ -0,0 +1,32 @@
+#include "fcts.h"
+
+int main(int argc, char ** argv){
+ int i, nRNG;
+ double nAcc=0;
+ if(argc < 2){
+ return -1;
+ }
+ nRNG = atoi(argv[1]);
+ double x, y;
+ long res[nRNG*2];
+ double max=0;
+ for (i = 0; i < nRNG; i++){
+ x = ((double) uniform())/(double)0x7FFFFFFF;
+ y = ((double) uniform())/(double)0x7FFFFFFF;
+ printf("x= %lf", x);
+ if (x > max)
+ max = x;
+ if (x *x + y * y <= 1){
+ nAcc ++;
+ }
+ res[2*i] = x;
+ res[2*i+1]=y;
+ }
+ printf("\n max = %lf \n", max);
+ int freqs[10];
+ for (i = 0; i < 10 ; i++)
+ freqs[i] = 0;
+ store_res(res, freqs, nRNG, 10);
+ double pi = 4 * nAcc/nRNG;
+ printf("%lf \n", pi);
+}
--
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