<html><head><meta http-equiv="Content-Type" content="text/html charset=windows-1252"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;"><div>Hi Matt & Chip </div><div><br></div>I concur that making the results useful to other people are important. I think beyond the<div>results of a particular fit, we also need to think about extracting and publishing ``observables’'</div><div>than anyone can then compare to their model. The simple ones are cross sections and polarization</div><div>and beam asymmetries, but there are more sophisticated ones that can also be extracted. SDMEs,</div><div>etc.</div><div><br></div><div> In principle, people can perform fits to these observables using their own models, etc….</div><div><br></div><div> curtis</div><div><br></div><div><br></div><div><br></div><div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><span class="Apple-style-span" style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; -webkit-text-decorations-in-effect: none; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><div>-------</div><div>Prof. Curtis A. Meyer<span class="Apple-tab-span" style="white-space: pre; "> </span> <span class="Apple-converted-space"> </span>Department of Physics</div><div>Phone: (412) 268-2745<span class="Apple-tab-span" style="white-space: pre; "> </span> <span class="Apple-converted-space"> </span>Carnegie Mellon University</div><div>Fax: (412) 681-0648<span class="Apple-tab-span" style="white-space: pre; "> </span> Pittsburgh, PA 15213</div><div><a href="mailto:curtis.meyer@cmu.edu">curtis.meyer@cmu.edu</a> <a href="http://www.curtismeyer.com/">http://www.curtismeyer.com/</a></div><div><br></div><div><br></div></div></span><br class="Apple-interchange-newline"></span><br class="Apple-interchange-newline">
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<br><div><div>On Jul 31, 2014, at 12:17 PM, Matthew Shepherd <<a href="mailto:mashephe@indiana.edu">mashephe@indiana.edu</a>> wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite"><br>Chip,<br><br>Making n-tuples available is a natural instinct, but<br>I don't think it will be practically useful.<br>To make a reanalysis useful you<br>not only need the four vectors, but also code to simulate<br>the detector and explore the acceptance of the new cuts.<br>Then you may need other data to understand the <br>systematic uncertainties in the cuts. Is is hard to<br>imagine someone doing a robust re-analysis without<br>complete access to the GlueX data set and software.<br>(Here I define "robust" as "capable of publishing<br>in a peer reviewed journal.") This is just my opinion --<br>I think we'll spend a lot of time doing this and people<br>may download and play with the data, but it will<br>just be playing. I don't think useful cross-checks<br>or additional publishable results can be obtained from<br>an ntuple alone.<br><br>Most key GlueX results won't be 1D histograms but <br>results of amplitude analyses. Each such analysis<br>will contain a lot of data -- likely thousands of fit<br>parameters, many of which will have non-trivial correlations.<br>These results are useful and able to be reanalyzed<br>as they will represent "pure quantities" (with<br>detector effects removed and systematic errors<br>quantified).<br><br>We should focus on a standard way to make the results<br>of GlueX amplitude analysis available to the <br>community with all the proper correlation matrices<br>etc. so that it can be reanalyzed. This is an<br>absolute necessity in the context of doing <br>combined fits from multiple experiments that people<br>talk about as a long term goal.<br><br>Matt<br><br>---------------------------------------------------------------------<br>Matthew Shepherd, Associate Professor<br>Department of Physics, Indiana University, Swain West 265<br>727 East Third Street, Bloomington, IN 47405<br><br>Office Phone: +1 812 856 5808<br><br>On Jul 31, 2014, at 12:02 PM, Chip Watson <<a href="mailto:watson@jlab.org">watson@jlab.org</a>> wrote:<br><br><blockquote type="cite">Concur, we don't want to generate unnecessary work for ourselves. I would suggest that just the data in a plot is insufficient. For example if what is show is a histogram (1D) which is the result of statistical analysis of 20GB of 4 vectors, then provide the 20GB file so others can try their own cuts on the data. So probably not the raw data, but probably the N-tuples. Yes, needs discussion and then specificity to satisfy the directive.<br><br>On 7/31/14 11:58 AM, Matthew Shepherd wrote:<br><blockquote type="cite">I think we need to define what "data" means in this case.<br>NSAC was briefed on this last summer and, as far as my<br>understanding goes, digital data can mean anything from<br>making the plots digitally available in PDF to providing<br>raw four-vectors, software, etc. to do a complete analysis.<br><br>I noticed that the third principle of the policy states:<br><br>"Not all data need to be shared or preserved. The costs and <br>benefits of doing so should be considered in data <br>management planning."<br><br>I think a good strategy to start with is to making available<br>in tabular form any data points, error bars, etc. that<br>appear in papers in refereed journals. <br>This seems to be optimal cost/benefit point as others <br>may want to do fits to cross sections,<br>extracted scattering amplitudes, etc. from GlueX data.<br>It is more useful than just a plot, but not as cumbersome<br>as making the raw data available. I don't think the<br>raw data would be of much use to most people anyway<br>without the insider experience to analyze it.<br><br>In this case the DOI would reference tabular data<br>that was relevant for plots in a particular journal article<br>(not terabytes of actual and simulated data).<br><br>Of course this needs more discussion and we need<br>to make sure that what we do is compliant with the<br>policy, but I'd argue for thinking about what is most<br>logical and useful first and see if it fits the guidelines<br>rather than trying to glean specific guidance from<br>what is a very general policy.<br><br>Matt<br><br></blockquote><br>_______________________________________________<br>Halld-offline mailing list<br><a href="mailto:Halld-offline@jlab.org">Halld-offline@jlab.org</a><br>https://mailman.jlab.org/mailman/listinfo/halld-offline<br></blockquote><br><br>_______________________________________________<br>Halld-offline mailing list<br><a href="mailto:Halld-offline@jlab.org">Halld-offline@jlab.org</a><br>https://mailman.jlab.org/mailman/listinfo/halld-offline<br></blockquote></div><br></div></body></html>