<div dir="ltr"><div><div>re: "<span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>for months with consecutive zero precipitation values, the corresponding SPI value is indicated as missing value (i.e. -999)."<br><br></span></span></font></span></div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>Given all 0s, the code is telling you that it could not calculate </span></span></font></span><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Pearson 3 distribution parameters.<br></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">EG: The mean would be 0.0, the standard deviation is 0.0. What would you expect the </span></font></span><br><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span></span></span></font></span><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Pearson 3 distribution parameters to be?<br><br></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">I believe I sent you the code used by NCL. This subroutine was developed by Hosking (IBM). You can follow the code to see waht leads to that message.<br><br></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Good Lucl<br></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><br> DOUBLE PRECISION FUNCTION CDFPE3(X,PARA,ifail,amssng)<br>C***********************************************************************<br>C* *<br>C* FORTRAN CODE WRITTEN FOR INCLUSION IN IBM RESEARCH REPORT RC20525, *<br>C* 'FORTRAN ROUTINES FOR USE WITH THE METHOD OF L-MOMENTS, VERSION 3' *<br>C* *<br>C* J. R. M. HOSKING *<br>C* IBM RESEARCH DIVISION *<br>C* T. J. WATSON RESEARCH CENTER *<br>C* YORKTOWN HEIGHTS *<br>C* NEW YORK 10598, U.S.A. *<br>C* *<br>C* VERSION 3 AUGUST 1996 *<br>C* *<br>C***********************************************************************<br>C<br>C DISTRIBUTION FUNCTION OF THE PEARSON TYPE 3 DISTRIBUTION<br>C<br><br></span></font></span></div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"></span></font></span></div><div class="gmail_extra"><br><div class="gmail_quote">On Sat, Jun 10, 2017 at 6:29 AM, Dawit Abebe <span dir="ltr"><<a href="mailto:dawit.kan@gmail.com" target="_blank">dawit.kan@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div><div><span style="color:rgb(255,0,0)">Dear All <br><br></span></div><span style="color:rgb(255,0,0)">Kindly your help on errors with SPI using Pearson Type 3 described below<br><br></span></div><span style="color:rgb(255,0,0)">Dawit</span><br><div><div><div><br><div class="gmail_quote"><span class="">---------- Forwarded message ----------<br>From: <b class="gmail_sendername">Dawit Abebe</b> <span dir="ltr"><<a href="mailto:dawit.kan@gmail.com" target="_blank">dawit.kan@gmail.com</a>></span><br>Date: 8 June 2017 at 15:43<br>Subject: SPI values derived using Pearson 3<br>To: <a href="mailto:ncl-talk-request@ucar.edu" target="_blank">ncl-talk-request@ucar.edu</a>, <a href="mailto:ncl-talk@ucar.edu" target="_blank">ncl-talk@ucar.edu</a>, Mary Haley <<a href="mailto:haley@ucar.edu" target="_blank">haley@ucar.edu</a>><br><br><br></span><div dir="ltr"><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Dear All,<br><br></span></font></span><div><span class=""><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Can any one help me understand the following error messages when calculating SPI based on Pearson 3
option. <br></span></font></span><br></span><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>Part of my script related to this is:<br>==============================<wbr>===============<br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>opt = True<br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>opt@spi_type = 3<br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>spi = new((/nrun, ntime, nlat, mlon/), typeof(prc), pmsg)<br><br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>do nr=0, nrun-1<br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span> spi(nr, :, :, :) = dim_spi_n(prc, run(r), opt, 0)<br></span></span></font></span><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>end do<br><br></span></span></font></span></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span style="font-family:arial,helvetica,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>However, <br></span></span></font></span></span></font></span></div><span class=""><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">1. I get the an error message: <span style="color:rgb(255,0,0)">"</span><span><span style="color:rgb(255,0,0)">*** ERROR *** ROUTINE CDFPE3 : PARAMETERS INVALID”</span> , why and what does this mean? I cam across a similar problem being reported but not responded to. <br><br></span></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>2.
After the above error message, however, NCL has generated the SPI values. However, for months with consecutive zero precipitation values, the corresponding SPI value is indicated as missing value (i.e. -999). The fact that Pearson 3 is advantageous over Gama that </span><span>where monthly and seasonal precipitation of zero is common,
it will give better results than Gama (<a href="http://www.ncl.ucar.edu/Document/Functions/Built-in/dim_spi_n.shtml" target="_blank">http://www.ncl.ucar.edu/Docum<wbr>ent/Functions/Built-in/dim_spi<wbr>_n.shtml</a>), I'm unsure why missing values (-999) generated for months and seasons with zero precipitation value. This is observed mainly on SPI calculate over 1 and 3 months time scale.<br><br></span></span></font></span></div><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span>I would very much appreciate if any me help me to understand and solve this two issues. <br></span></span></font></span></div><span class="m_6005021292341209079gmail-m_-4915457008815115858HOEnZb"><font color="#888888"><div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)"><span><br></span></span></font></span></div><span style="font-family:comic sans ms,sans-serif"><font size="2"><span style="color:rgb(0,0,255)">Dawit</span></font></span><br></font></span></span></div>
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