From d34ebdb431522b9e69473fd502f77cf4b124306d Mon Sep 17 00:00:00 2001 From: Miroslav Lichvar Date: Thu, 9 Jan 2014 18:17:57 +0100 Subject: [PATCH] Simplify expression used in frequency accumulation --- local.c | 4 ++-- rtc_linux.c | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/local.c b/local.c index e4be12b..9276ee5 100644 --- a/local.c +++ b/local.c @@ -411,7 +411,7 @@ LCL_AccumulateDeltaFrequency(double dfreq) are handled in units of ppm, whereas the 'dfreq' argument is in terms of the gradient of the (offset) v (local time) function. */ - current_freq_ppm = (1.0 - dfreq) * current_freq_ppm + 1.0e6 * dfreq; + current_freq_ppm += dfreq * (1.0e6 - current_freq_ppm); /* Call the system-specific driver for setting the frequency */ current_freq_ppm = (*drv_set_freq)(current_freq_ppm); @@ -508,7 +508,7 @@ LCL_AccumulateFrequencyAndOffset(double dfreq, double doffset, double corr_rate) /* Work out new absolute frequency. Note that absolute frequencies are handled in units of ppm, whereas the 'dfreq' argument is in terms of the gradient of the (offset) v (local time) function. */ - current_freq_ppm = (1.0 - dfreq) * old_freq_ppm + 1.0e6 * dfreq; + current_freq_ppm += dfreq * (1.0e6 - current_freq_ppm); DEBUG_LOG(LOGF_Local, "old_freq=%.3fppm new_freq=%.3fppm offset=%.6fsec", old_freq_ppm, current_freq_ppm, doffset); diff --git a/rtc_linux.c b/rtc_linux.c index 3fcf297..8eda906 100644 --- a/rtc_linux.c +++ b/rtc_linux.c @@ -282,7 +282,7 @@ slew_samples if (coefs_valid) { coef_seconds_fast += doffset; - coef_gain_rate = (1.0 - dfreq) * coef_gain_rate + dfreq; + coef_gain_rate += dfreq * (1.0 - coef_gain_rate); } DEBUG_LOG(LOGF_RtcLinux, "dfreq=%.8f doffset=%.6f old_fast=%.6f old_rate=%.3f new_fast=%.6f new_rate=%.3f",