<html><body><div style="font-family: arial, helvetica, sans-serif; font-size: 12pt; color: #000000"><div><br data-mce-bogus="1"></div><div>Hi Dennis,</div><div><br data-mce-bogus="1"></div><div>Thanks for your information. That s really helpful.</div><div><br data-mce-bogus="1"></div><div> BRGs,<br></div><div><br data-mce-bogus="1"></div><div>Kritanai T.<br data-mce-bogus="1"></div><div><br></div><hr id="zwchr" data-marker="__DIVIDER__"><div data-marker="__HEADERS__"><b>จาก: </b>"Dennis Shea" <shea@ucar.edu><br><b>ถึง: </b>"Kritanai Torsri (HAII User)" <kritanai@haii.or.th><br><b>สำเนา: </b>"ncl-talk" <ncl-talk@ucar.edu><br><b>ส่งแล้ว: </b>พฤหัสบดี, 30 มิถุนายน, 2016 6:31:11 AM<br><b>เรื่อง: </b>Re: [ncl-talk] How "dim_spi_n" deal with zero precipitaion and maps cdf into spi values??<br></div><div><br></div><div data-marker="__QUOTED_TEXT__"><div dir="ltr">NCL uses a f77 subroutine based upon a code originally created by the USA's National Climate Data Center (now known as the <a title="National Centers for Environmental Information" href="https://en.wikipedia.org/wiki/National_Centers_for_Environmental_Information" target="_blank" data-mce-href="https://en.wikipedia.org/wiki/National_Centers_for_Environmental_Information">National Centers for Environmental Information</a> (NCEI). It contains the following code comments.<br><sup id="cite_ref-ncei.noaa.gov_2-0"></sup><div><br>c OUTPUT: par1,par2,par3 parameters (mean, s.d., skewness) of<br>c Pearson Type III distribution used to<br>c fit the input data > 0<br>c xmom1,xmom2,xmom3 l-moments of the input data > 0<br>c pzero relative frequency of input data = 0<br><br></div><div>So, without looking at the code in detail, I'd say 0s are ignored.<br><br></div><div>If you want to see the code, I have placed the code at<br></div><div><br><a href="http://www.cgd.ucar.edu/~shea/spi3.f" target="_blank" data-mce-href="http://www.cgd.ucar.edu/~shea/spi3.f">http://www.cgd.ucar.edu/~shea/spi3.f</a><br><br></div><div>Good luck<br></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Jun 29, 2016 at 7:39 AM, Kritanai Torsri (HAII User) <span dir="ltr"><<a href="mailto:kritanai@haii.or.th" target="_blank" data-mce-href="mailto:kritanai@haii.or.th">kritanai@haii.or.th</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;" data-mce-style="margin: 0 0 0 .8ex; border-left: 1px #ccc solid; padding-left: 1ex;"><div><div style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000;" data-mce-style="font-family: arial,helvetica,sans-serif; font-size: 12pt; color: #000000;"><div>Dear ALL,<br></div><br><div>Can any one help me to clarify how "dim_spi_n" deals with zero precipitation for both fitting with 2-param Gamma distribution and Pearson Type 3?</div><br><div>and how it maps cumulative distribution function (cdf) into SPI values?</div><br><div>Thanks in advance.</div><br><div>BRGs,<br></div><br><div>Kritanai T.<br></div><br><div> <br></div></div></div><br>_______________________________________________<br> ncl-talk mailing list<br> <a href="mailto:ncl-talk@ucar.edu" target="_blank" data-mce-href="mailto:ncl-talk@ucar.edu">ncl-talk@ucar.edu</a><br> List instructions, subscriber options, unsubscribe:<br> <a href="http://mailman.ucar.edu/mailman/listinfo/ncl-talk" target="_blank" rel="noreferrer" data-mce-href="http://mailman.ucar.edu/mailman/listinfo/ncl-talk">http://mailman.ucar.edu/mailman/listinfo/ncl-talk</a><br> <br></blockquote></div></div><br></div></div></body></html>