Displaying 1 result from an estimated 1 matches for "r_euclidean2".
2010 Jan 22
2
Optimizing C code
...read the code 
for the Euclidean distance.
I do not understand the purpose of the line 11 : if x[i] and y[i] are 
not NA (line 9), can dev be NA ?
Christophe
#define both_FINITE(a,b) (R_FINITE(a) && R_FINITE(b))
#define both_non_NA(a,b) (!ISNAN(a) && !ISNAN(b))
1. static double R_euclidean2(double *x, double *y, int taille)
2. {
3.    double dev, dist;
4.    int count, i;
5.
6.    count= 0;
7.    dist = 0;
8.    for(i = 0 ; i < taille ; i++) {
9.    if(both_non_NA(x[i], y[i])) {
10.        dev = (x[i] - y[i]);
11.        if(!ISNAN(dev)) {
12.        dist += dev * dev;
13.        co...