int stratified_resampling(struct particle p[], int N){
static double s;
double sum[N];
cum_sum(p,sum,N);
double x = randu(s,s+(1.0/N));
int index;
for(int i = 0;i<N;i++){
if(sum[i]>x){
//free(sum);
index = i;
break;
}
}
//printf("\t%f\t%f\t%f\n",x,sum[0],sum[N-1]);
s += (double)(1.0/N);
if((1-s)<0.1/N)
s = 0;
return index;
}
int systematic_resampling(struct particle p[], int N){
static int s;
s++;
double sum[N];
cum_sum(p,sum,N);
double x = randu(0,(1.0/N));
x += (float)(s-1.0)/N; // systematic resampling
int index;
for(int i = 0;i<N;i++){
if(sum[i]>x){
//free(sum);
index = i;
break;
}
}
if(N == s)
s = 0;
return index;
}
BOOST_SYMBOL_EXPORT
void cum_sum(double const *src, double *dst, size_t length,
BOOST_SIMD_DEFAULT_SITE)
{
one_dimension_source<cum_sum_tag> f
= one_dimension_source<cum_sum_tag>(src, dst, length);
cum_sum(f);
}
JNI_METHOD(void, cumSum)(JNIEnv *env, jobject,
jdoubleArray jsrc, jint src_offset,
jdoubleArray jdst, jint dst_offset,
jint length)
{
jdouble *src = (jdouble *) env->GetPrimitiveArrayCritical(jsrc, NULL);
jdouble *dst = (jdouble *) env->GetPrimitiveArrayCritical(jdst, NULL);
source_1d<cum_sum_tag> f(src + src_offset, dst + dst_offset, length);
cum_sum(f);
env->ReleasePrimitiveArrayCritical(jsrc, src, JNI_ABORT);
env->ReleasePrimitiveArrayCritical(jdst, dst, JNI_ABORT);
}
int
multimodal_resampling(struct particle p[], int N)
{
//double *sum;
//sum = (double*)calloc(N,sizeof(double));
double sum[N];
cum_sum(p,sum,N);
double x = randu(0,1);
for(int i = 0;i<N;i++){
if(sum[i]>x){
//free(sum);
return i;
}
}
return -1; //error
}
