tansig_approx    1232 libavfilter/af_arnndn.c     return .5f + .5f*tansig_approx(.5f*x);
tansig_approx    1254 libavfilter/af_arnndn.c             output[i] = tansig_approx(output[i]);
tansig_approx    1303 libavfilter/af_arnndn.c             sum = tansig_approx(WEIGHTS_SCALE * sum);