Am 09.07.19 um 00:25 schrieb Ulf Zibis:
Hi,
are there such functions in the FFmpeg library?
I have an integer array with lets say 13 numbers (accumulated counts of X in the range of 0..12) like: a) 0 1 0 1 2 7 9 5 4 3 2 0 1 b) 7 1 9 8 1 6 2 0 0 1 9 1 0
In a) the average X would be ~6 and the variance would be small. In b) the average X would be ~3.5 and the variance would be bigger.
I'm looking for functions that can calulate such values with a result in float resolution.
-Ulf For a qudratic average I could use something like: float sum = 0; for (int i = s->span_r - s->span_l; i >= 0; i--) sum += pow(counts[i], 2); float qaverage = sqrt(sum / (s->span_r - s->span_l + 1));
But for calculating the variance I'm lost. I assume, there are already solutions for both in the FFmpeg lib. -Ulf