Path: csiph.com!x330-a1.tempe.blueboxinc.net!newsfeed.hal-mli.net!feeder1.hal-mli.net!border3.nntp.dca.giganews.com!Xl.tags.giganews.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local2.nntp.dca.giganews.com!nntp.earthlink.com!news.earthlink.com.POSTED!not-for-mail NNTP-Posting-Date: Sun, 10 Apr 2011 20:14:10 -0500 Newsgroups: comp.graphics.apps.gnuplot From: Charles Allen Subject: Re: Fitting: How does gnuplot calculate the covariance matrix? References: <9088euFi3iU1@mid.individual.net> <908n9pF2jaU1@mid.individual.net> <90e7s7F9faU1@mid.dfncis.de> User-Agent: slrn/pre1.0.0-18 (Linux) Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Message-ID: Date: Sun, 10 Apr 2011 20:14:11 -0500 Lines: 18 X-Usenet-Provider: http://www.giganews.com NNTP-Posting-Host: 75.111.234.191 X-Trace: sv3-jOhQekio28cT9L96B1yZx/ZofXd3bDqbt0QlJG5D8OwU7HvuzVW0RbFi3hzDyS5QNMM5lIzM2C+9XJl!DsF2KtOgR1kIG+zZF1agwLSSBtfileEmvkXE7fUqjW97yENZ0e1Zqs0JerjRLbTAyg+0idkj28Mq!Uvbvf5u6nu2GyGZIL56VEhzf X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.40 X-Original-Bytes: 1750 Xref: x330-a1.tempe.blueboxinc.net comp.graphics.apps.gnuplot:228 > On 08.04.2011 17:18, Ingo Thies wrote: >> Another point seems to be even more problematic, that is the usage of >> the "asymptotic standard error". Hans-Bernhard Bröker: > Those errors are _way_ too big. Do yourself a favour and plot your data > along with the model, using parameters modified by those errors: Perhaps there is confusion about "standard error" (error on the mean) versus standard deviation. The factor of 1/sqrt(21) (or however many data points there were) seems about right. Gnuplot is reporting the error on the mean, the other program may be reporting the standard deviation. -- Charles Allen