| | |
| | | void top_k(float *a, int n, int k, int *index) |
| | | { |
| | | int i,j; |
| | | float thresh = FLT_MAX; |
| | | for(i = 0; i < k; ++i){ |
| | | float max = -FLT_MAX; |
| | | int max_i = -1; |
| | | for(j = 0; j < n; ++j){ |
| | | float val = a[j]; |
| | | if(val > max && val < thresh){ |
| | | max = val; |
| | | max_i = j; |
| | | for(j = 0; j < k; ++j) index[j] = 0; |
| | | for(i = 0; i < n; ++i){ |
| | | int curr = i; |
| | | for(j = 0; j < k; ++j){ |
| | | if(a[curr] > a[index[j]]){ |
| | | int swap = curr; |
| | | curr = index[j]; |
| | | index[j] = swap; |
| | | } |
| | | } |
| | | index[i] = max_i; |
| | | thresh = max; |
| | | } |
| | | } |
| | | |
| | | void error(char *s) |
| | | { |
| | | fprintf(stderr, "Error: %s\n", s); |
| | | perror(s); |
| | | //fprintf(stderr, "Error: %s\n", s); |
| | | exit(0); |
| | | } |
| | | |
| | |
| | | char *fgetl(FILE *fp) |
| | | { |
| | | if(feof(fp)) return 0; |
| | | unsigned long size = 512; |
| | | size_t size = 512; |
| | | char *line = malloc(size*sizeof(char)); |
| | | if(!fgets(line, size, fp)){ |
| | | free(line); |
| | | return 0; |
| | | } |
| | | |
| | | int curr = strlen(line); |
| | | size_t curr = strlen(line); |
| | | |
| | | while(line[curr-1]!='\n'){ |
| | | while((line[curr-1] != '\n') && !feof(fp)){ |
| | | printf("%ld %ld\n", curr, size); |
| | | size *= 2; |
| | | line = realloc(line, size*sizeof(char)); |
| | | if(!line) { |
| | |
| | | fgets(&line[curr], size-curr, fp); |
| | | curr = strlen(line); |
| | | } |
| | | line[curr-1] = '\0'; |
| | | if(line[curr-1] == '\n') line[curr-1] = '\0'; |
| | | |
| | | return line; |
| | | } |
| | |
| | | a[i] *= s; |
| | | } |
| | | } |
| | | |
| | | int max_index(float *a, int n) |
| | | { |
| | | if(n <= 0) return -1; |
| | |
| | | return max_i; |
| | | } |
| | | |
| | | // From http://en.wikipedia.org/wiki/Box%E2%80%93Muller_transform |
| | | #define TWO_PI 6.2831853071795864769252866 |
| | | float rand_normal() |
| | | { |
| | | int i; |
| | | float sum= 0; |
| | | for(i = 0; i < 12; ++i) sum += (float)rand()/RAND_MAX; |
| | | return sum-6.; |
| | | static int haveSpare = 0; |
| | | static double rand1, rand2; |
| | | |
| | | if(haveSpare) |
| | | { |
| | | haveSpare = 0; |
| | | return sqrt(rand1) * sin(rand2); |
| | | } |
| | | |
| | | haveSpare = 1; |
| | | |
| | | rand1 = rand() / ((double) RAND_MAX); |
| | | if(rand1 < 1e-100) rand1 = 1e-100; |
| | | rand1 = -2 * log(rand1); |
| | | rand2 = (rand() / ((double) RAND_MAX)) * TWO_PI; |
| | | |
| | | return sqrt(rand1) * cos(rand2); |
| | | } |
| | | |
| | | /* |
| | | float rand_normal() |
| | | { |
| | | int n = 12; |
| | | int i; |
| | | float sum= 0; |
| | | for(i = 0; i < n; ++i) sum += (float)rand()/RAND_MAX; |
| | | return sum-n/2.; |
| | | } |
| | | */ |
| | | |
| | | float rand_uniform() |
| | | { |
| | | return (float)rand()/RAND_MAX; |