And, in the structural world, root mean square distance fluctuation is given by deltaRMSD = sqrt[(x2 - x1)^2 + (y2 - y1)^2 + (z2 - z1)^2] where x, y and z are 3-dimensional Cartesian coordinates, usually the position of an atom. This might be used to determine the difference between two protein structures, for example. Jeff Allen Henry wrote: > > I'm only a student in the BioInfo biz, but am very > good at math and come from an image processing > background where we called this the Root Mean Square > Error (RMSE). I recognized this right away because one > of my first 'bugs' that I fixed was in this very same > function. I found something on Google's groups with a > similar question as well as the equation: > > http://thesaurus.maths.org/dictionary/map/word/3701 > > I hope this of help > > :-) > > ======================================================= > > Hi all, > > Given a set of of tiepoints for images and/or maps, > how should one go about calculating the RMSE? This is > with respect to surface fitting models for image > registration > and rectification. Such methods include polynomials > and piecewise linear functions. No prior assumptions > 'bout anything. This, of course, rules out kriging > for rubber-sheeting... well, not exactly, but that's a > question for another day. > > So, given that this is a matter of developing a > deterministic model, would YOU account for degrees of > freedom? Two alternatives follow below for > polynomials. > > (1) > RMS for X = sqrt ( sum( (residual X)**2 ) / (N - K) > ) > RMS for Y = sqrt ( sum( (residual Y)**2 ) / (N - K) > ) > RMS Distance = sqrt ( (RMS for X)**2 + (RMS for Y)**2 > ) > > (2) > RMS for X = sqrt ( sum( (residual X)**2 ) / N ) > RMS for Y = sqrt ( sum( (residual Y)**2 ) / N) ) > RMS Distance = sqrt ( (RMS for X)**2 + (RMS for Y)**2 > ) > > where, > > N is the number of GCPs and K is the number of terms > for the specified order. > > Regards. > > -David > fogel at geog.ucsb.edu > > Hope this Helps > --- biodevelopers-request at bioinformatics.org wrote: > > Send Biodevelopers mailing list submissions to > > biodevelopers at bioinformatics.org > > > > To subscribe or unsubscribe via the World Wide Web, > > visit > > > > > http://bioinformatics.org/mailman/listinfo/biodevelopers > > or, via email, send a message with subject or body > > 'help' to > > biodevelopers-request at bioinformatics.org > > > > You can reach the person managing the list at > > biodevelopers-admin at bioinformatics.org > > > > When replying, please edit your Subject line so it > > is more specific > > than "Re: Contents of Biodevelopers digest..." > > > > > > Today's Topics: > > > > 1. Re: [BiO BB] delta RMS (Joseph Landman) > > > > --__--__-- > > > > Message: 1 > > From: Joseph Landman > > <landman at scalableinformatics.com> > > To: bio_bulletin_board at bioinformatics.org > > Cc: biodevelopers <biodevelopers at bioinformatics.org> > > Date: 18 Aug 2002 22:08:34 -0400 > > Subject: [Biodevelopers] Re: [BiO BB] delta RMS > > Reply-To: biodevelopers at bioinformatics.org > > > > Hi Pete: > > > > RMS deviation (also known as standard deviation) > > is generally well > > defined. Could what you have be > > > > delta (RMS deviation)[i,j] = SD(i) - SD(j) > > > > basically using the delta as a difference operator > > between two different > > SD's? This might be one of several possible > > "signatures" that an > > analysis would use to compare measurement > > distributions, or set > > thresholds for sub-sampling to help delineate > > clusters. > > > > > > On Sun, 2002-08-18 at 21:54, Peter oledzki wrote: > > > Hello, > > > > > > I'm working on a project at the moment and I've > > come > > > across something called delta root mean squared > > > deviation....does anybody know what this is? > > > > > > Could they possily try and explain it to me.....? > > > > > > Any help would be much appreciated. -- J.W. Bizzaro jeff at bioinformatics.org Director, Bioinformatics.Org http://bioinformatics.org/~jeff "As we enjoy great advantages from the inventions of others, we should be glad of an opportunity to serve others by any invention of ours; and this we should do freely and generously." -- Benjamin Franklin --