<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 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><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)">1. I get the an error message: "<span>*** ERROR *** ROUTINE CDFPE3 : PARAMETERS INVALID” , 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">http://www.ncl.ucar.edu/Document/Functions/Built-in/dim_spi_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><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></div>