From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from fireflyinternet.com (unknown [77.68.26.236]) by gabe.freedesktop.org (Postfix) with ESMTPS id E63A86EC1F for ; Tue, 3 Nov 2020 10:49:04 +0000 (UTC) MIME-Version: 1.0 In-Reply-To: <20201102090836.19803-1-anandx.ram.moon@intel.com> References: <20201102090836.19803-1-anandx.ram.moon@intel.com> From: Chris Wilson Date: Tue, 03 Nov 2020 10:49:00 +0000 Message-ID: <160440054042.21466.14289928033719881030@build.alporthouse.com> Subject: Re: [igt-dev] [i-g-t] tests/kms_setmode: basic Improve accuracy with using of confidence interval List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" To: Anand Moon , igt-dev@lists.freedesktop.org Cc: Anand Moon List-ID: Quoting Anand Moon (2020-11-02 09:08:36) > Using confidence interval formula accuracy is estimates approximately > at 95% when {X} is the average of a sample of size n. > Use this confidence interval formula as used in statistics > to estimate the accuracy. > > Signed-off-by: Anand Moon > --- > See below link. > https://en.wikipedia.org/wiki/68%E2%80%9395%E2%80%9399.7_rule#Cumulative_distribution_function > --- > tests/kms_setmode.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/tests/kms_setmode.c b/tests/kms_setmode.c > index 92f3ead2..58814a13 100644 > --- a/tests/kms_setmode.c > +++ b/tests/kms_setmode.c > @@ -494,7 +494,7 @@ static void check_timings(int crtc_idx, const drmModeModeInfo *kmode) > * which depend on timing, giving the lowest acceptable MTBF of 5.6s > * for 60Hz sampling rate. > */ > - accuracy = 3. * stddev; > + accuracy = 3. * stddev / sqrt(CALIBRATE_TS_STEPS); Oops, yes, this should be standard error rather than deviation. Could you add igt_stats_get_std_error() so we don't hardcode N? -Chris _______________________________________________ igt-dev mailing list igt-dev@lists.freedesktop.org https://lists.freedesktop.org/mailman/listinfo/igt-dev