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<DIV>Thanks Patrick and Chad for the information about error estimates from F-statistics.</DIV>
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<DIV>My problem now is that the apparent errors for the binding constants derived from the analysis of F-statistic appear to be very large. When I make a change to e.g. log10Ka12, by any value from 0.1 - 3.0, there is no change (or only a very small change) in chi squared, so I can never reach the critical chi squared. </DIV>
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<DIV>Each dataset looks good and gives low rmsd values when processing with the c(s) model in sedfit. I'm using the monomer-dimer self-association model in sedphat, with the values for S1 and S2 taken from c(s) analysis. I have tried to fit to other models with only worse results.</DIV>
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<DIV>The fit looks very poor (see screenshots attached). I don't think I need to repeat the experiment because the data looks good, at least to my eye, but the fit to the monomer-dimer model seems very bad. </DIV>
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<DIV>Any further suggestions or advice would be very welcome.</DIV>
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<DIV>Many Thanks,</DIV>
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<DIV>Mark</DIV>
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<DIV>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<BR>Dr Mark Agacan, Scientific Officer for the Division of Biological Chemistry and Drug Discovery,<BR>Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee, DD1 5EH <BR>Tel: +44 1382 386095 Fax: +44 1382 345764 Mobile: 07525 451 117<BR>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</DIV>
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<DIV><FONT color=#666666>Please consider the environment. Do you really need to print this email?</FONT> </DIV></DIV><BR><BR>>>> Chad Brautigam <Chad.Brautigam@UTSouthwestern.edu> 4/23/2011 15:02 >>><BR></DIV>
<DIV style="FONT-SIZE: 10pt; COLOR: #000000; DIRECTION: ltr; FONT-FAMILY: Tahoma">Hi, Mark,<BR><BR>The F-statistics in SEDPHAT are meant to allow you to construct a "do-it-yourself" error interval. Check out the statistics help page. Under the heading "Error Analysis" there is a procedure for how to use the output "critical chi-square" from the Statistics Menu to find an error interval.<BR><BR>Cheers,<BR>Chad<BR><BR>
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<DIV id=divRpF398298 style="DIRECTION: ltr"><FONT face=Tahoma color=#000000 size=2><B>From:</B> rasmb-bounces@rasmb.bbri.org [rasmb-bounces@rasmb.bbri.org] on behalf of Mark Agacan [M.Agacan@dundee.ac.uk]<BR><B>Sent:</B> Friday, April 22, 2011 6:36 AM<BR><B>To:</B> rasmb@rasmb-email.bbri.org<BR><B>Subject:</B> [RASMB] error estimates and F-statistics in Sedphat<BR></FONT><BR></DIV>
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<DIV>Hello,</DIV>
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<DIV>I'm calculating errors in the binding constants in sedphat as instructed in the statistics help page, but I don't appear to get an output for the F-statistics. Are the F-stats output only as (changes in) chi-squared values? e.g. the error associated with the binding constants is clearly given in the covariance matrix.</DIV>
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<DIV>Best Wishes,</DIV>
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<DIV>Mark</DIV>
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<DIV>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<BR>Dr Mark Agacan, Scientific Officer for the Division of Biological Chemistry and Drug Discovery,<BR>Wellcome Trust Biocentre, College of Life Sciences, University of Dundee, Dundee, DD1 5EH <BR>Tel: +44 1382 386095 Fax: +44 1382 345764 Mobile: 07525 451 117<BR>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</DIV>
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<DIV><FONT color=#666666>Please consider the environment. Do you really need to print this email?</FONT> </DIV></DIV><BR>
<P>The University of Dundee is a registered Scottish charity, No: SC015096 </P></DIV></DIV></DIV><BR>
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