Re: regress versus fit -
- To: mathgroup at smc.vnet.net
- Subject: [mg61526] Re: [mg61493] regress versus fit -
- From: "David Annetts" <davidannetts at aapt.net.au>
- Date: Fri, 21 Oct 2005 00:38:11 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Hi Chris, > It seems like the diagnostics returned by Regress are okay, > but they don't have any significance arithmetic ability. > Looks like I will be doing each problem twice... once for the > regression report, and once for the "significance arithmetic" > available with Fit. > David, do you work for WRI? You said you looked at the "code" > for Regress... I was thinking about filing a bug report or > RFE to have Regress' BestFit return the same result as Fit > for "bignum"/"sig. > arithmetic" inputs. Good idea y/n? Sounds like a great idea to me. That best fit coefficients have higher precision than the data they approximate doesn't seem right. I don't work for WRI. Looking at the code is no great mystery, at least in this case. Statistics`LinearRegression is a standard package, which means that it resides somewhere on the computer. All I did was go to the directory StringJoin[$InstallationDirectory, "\\AddOns\\StandardPackages"] and then to the Statistics subdirectory where I could open LinearRegression.m with a text editor (you can also use the Front End). If the package is not encrypted, then you can read it, and if it is, then it's for a good reason. You can do this for standard packages which are not in Experimental, Developer or RealTime3D contexts, and it's a great exercise for those who want to get deeper into the system, or those who need a bit more than is provided and are willing to get their hands dirty. Regards, Dave.