480     double* xf = _xf->data.db;  in calc_activ_func_deriv()  local
487         for( i = 0; i < n; i++, xf += cols, df += cols )  in calc_activ_func_deriv()
490                 xf[j] += bias[j];  in calc_activ_func_deriv()
499         for( i = 0; i < n; i++, xf += cols, df += cols )  in calc_activ_func_deriv()
502                 double t = xf[j] + bias[j];  in calc_activ_func_deriv()
504                 xf[j] = t*t*scale;  in calc_activ_func_deriv()
510         for( i = 0; i < n; i++, xf += cols, df += cols )  in calc_activ_func_deriv()
512                 xf[j] = (xf[j] + bias[j])*scale;  in calc_activ_func_deriv()
518     xf -= n; df -= n;  in calc_activ_func_deriv()
529             double x0 = 1.+xf[i], x1 = 1.+xf[i+1], x2 = 1.+xf[i+2], x3 = 1.+xf[i+3];  in calc_activ_func_deriv()
534             df[i] = scale*xf[i]*t0*t0;  in calc_activ_func_deriv()
535             df[i+1] = scale*xf[i+1]*t1*t1;  in calc_activ_func_deriv()
537             xf[i] = t0; xf[i+1] = t1;  in calc_activ_func_deriv()
540             df[i+2] = scale*xf[i+2]*t0*t0;  in calc_activ_func_deriv()
541             df[i+3] = scale*xf[i+3]*t1*t1;  in calc_activ_func_deriv()
543             xf[i+2] = t0; xf[i+3] = t1;  in calc_activ_func_deriv()
548             double t0 = 1./(1. + xf[i]);  in calc_activ_func_deriv()
549             double t1 = scale*xf[i]*t0*t0;  in calc_activ_func_deriv()
550             t0 *= scale2*(1. - xf[i]);  in calc_activ_func_deriv()
552             xf[i] = t0;  in calc_activ_func_deriv()
558             df[i] *= xf[i];  in calc_activ_func_deriv()