<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">No surprise that you do not understand, I'll try in the future to talk more Weygand like, if my blood pressure will allow it.</div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">What I am saying is, there is nothing special about that vert2 function. I have been using an exact code in ROOT. This function is the function I mentioned during the last G12 meeting, but it was obvious you checked out of the conversation at that point. </div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">R = 1 is the code syntax not mine, my ROOT code reads R = 1., which happens often for lepton pairs.</div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">Plots are coming today, </div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br></div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); ">We have been over what "BR" means 3 times now, this would make it a 4th. BR is shorthand for Best Regards.</div><div style="-webkit-tap-highlight-color: rgba(26, 26, 26, 0.296875); -webkit-composition-fill-color: rgba(175, 192, 227, 0.230469); -webkit-composition-frame-color: rgba(77, 128, 180, 0.230469); "><br>BR<div>MK</div></div><br>BR<div>MK</div><div><br></div><div>Sent from my iPhone</div></div><div><br>On Mar 22, 2013, at 9:51, Dennis Weygand <<a href="mailto:weygand@jlab.org">weygand@jlab.org</a>> wrote:<br><br></div><blockquote type="cite"><div>Not sure what you are saying here....<div><br></div><div><br></div><div><br><div><div>On Mar 20, 2013, at 10:32 PM, Michael C. Kunkel wrote:</div><br class="Apple-interchange-newline"><blockquote type="cite">
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Greetings,<br>
<br>
I looked into the workings of vert2. The method of obtaining the
vertex for 2 tracks in this method is no different than the method I
have been using for years. The problem with this method is that it
will fail if the tracks are parallel, which is usually the case for
conversions and low mass e+e- events (the problem are in which we
are investigating).<br>
<br>
Below is a the snipet of the code to prove it<br>
<br>
<font color="#3366ff"> /*calculate dot product of direction unit
vectors*/<br>
R = v3dot(line1.dir,line2.dir);<br></font></div></blockquote><div><br></div><div>R will never be '1' as R is I suspect a float (or double)</div><br><blockquote type="cite"><div text="#000000" bgcolor="#FFFFFF"><font color="#3366ff">
<br>
if(R==1){ /*parallel to beamline*/<br>
/*returns a negative distance so know that it was not
calculated*/ <br>
return;<br>
}</font><br>
<br>
In this case beamline is not used, this is a regurgitated function
used for another program that calculates the vertex of a particles
from the beamline if # of tracks ==1, otherwise all tracks in TBTR.<br>
<br>
I will provide plots tomorrow, I wanted to give a heads up about the
code, and why this might not be useful for either side of the
conversion debate.<br></div></blockquote><div><br></div>Do you have the plots?</div><div><br><blockquote type="cite"><div text="#000000" bgcolor="#FFFFFF">
<br>
BR<br></div></blockquote><div><br></div><div><br></div><div>I understand the MK, but who is BR?</div><div><br></div><br><blockquote type="cite"><div text="#000000" bgcolor="#FFFFFF">
MK<br>
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_______________________________________________<br>G12 mailing list<br><a href="mailto:G12@jlab.org">G12@jlab.org</a><br><a href="https://mailman.jlab.org/mailman/listinfo/g12">https://mailman.jlab.org/mailman/listinfo/g12</a><br></blockquote></div><br><div apple-content-edited="true">
<span class="Apple-style-span" style="border-collapse: separate; border-spacing: 0px; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space; "><span class="Apple-style-span" style="border-collapse: separate; -webkit-border-horizontal-spacing: 0px; -webkit-border-vertical-spacing: 0px; color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; -webkit-text-decorations-in-effect: none; text-indent: 0px; -webkit-text-size-adjust: auto; text-transform: none; orphans: 2; white-space: normal; widows: 2; word-spacing: 0px; "><div>--</div><div>Dennis Weygand</div><div><a href="mailto:weygand@jlab.org">weygand@jlab.org</a></div><div>(757) 269-5926 (office)</div><div>(757) 870-4844 (cell)</div><div><br class="khtml-block-placeholder"></div><br class="Apple-interchange-newline"></span></div></span></span><br class="Apple-interchange-newline">
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