diff options
| -rw-r--r-- | src/scalar.c | 44 |
1 files changed, 25 insertions, 19 deletions
diff --git a/src/scalar.c b/src/scalar.c index 74e3486..934f14e 100644 --- a/src/scalar.c +++ b/src/scalar.c @@ -397,29 +397,35 @@ int xtract_tristimulus_3(const double *data, const int N, const void *argv, doub int xtract_smoothness(const double *data, const int N, const void *argv, double *result) { - int n, M; - - double *input; - - input = (double *)malloc(N * sizeof(double)); - memcpy(input, data, N * sizeof(double)); - - if (input[0] <= 0) - input[0] = XTRACT_LOG_LIMIT; - if (input[1] <= 0) - input[1] = XTRACT_LOG_LIMIT; + int n; + int M = N - 1; + double prev = 0.0; + double current = 0.0; + double next = 0.0; + double temp = 0.0; - M = N - 1; + for(n = 1; n < M; n++) { - if(input[n+1] <= 0) - input[n+1] = XTRACT_LOG_LIMIT; - *result += fabs(20.0 * log(input[n]) - (20.0 * log(input[n-1]) + - 20.0 * log(input[n]) + 20.0 * log(input[n+1])) / 3.0); - } - - free(input); + if(n == 1) + { + prev = data[n-1] <= 0 ? XTRACT_LOG_LIMIT : data[n-1]; + current = data[n] <= 0 ? XTRACT_LOG_LIMIT : data[n]; + } + else + { + prev = current; + current = next; + } + + next = data[n+1] <= 0 ? XTRACT_LOG_LIMIT : data[n+1]; + + temp += fabs(20.0 * log(current) - (20.0 * log(prev) + + 20.0 * log(current) + 20.0 * log(next)) / 3.0); + } + + *result = temp; return XTRACT_SUCCESS; } |