<div dir="ltr">Dear all,<div><br></div><div>I&#39;ve been struggling with this issue for the last days without any glimpse of solution.</div><div><br></div><div>I&#39;m trying to calculate the difference between two fields from different models with different grids and similar resolutions (see ctl info and code below).</div>


<div><br></div><div>One is a netcdf file from E-OBS ECAD and the other one a grib file from WRF (previous a netcdf converted to grib with the UPP tool and then used the grib2ctl and gribmap to create the ctl and the idx files, respectively).</div>


<div><br></div><div>Each time I tried to calculated the difference between both fields I&#39;ve got the following message:</div><div><br></div><div><div>Data Request Error: Invalid grid coordinates</div>
<div>   World coordinates convert to non-integer  grid coordinates                                                                                                </div><div>   Variable = apcpsfc.2  Dimension = 3                                                                                                                     </div>


<div>   Error ocurred at column 1                                                                                                                                 </div><div>DEFINE error:  Invalid expression.</div></div><div>


<br></div><div><br></div><div>I&#39;d tried to work around with regrid but still with the same results.</div><div>Any help will be much appreciated.</div><div><br></div><div>Tanks in advance,</div>
<div>Susana Cardoso</div><div><br></div><div><br></div><div><br></div><div>Code </div><div>-------------------------------------------------------------------------------</div><div>
sdfopen <a href="http://eobs_rr.nc" target="_blank">eobs_rr.nc</a>                                                     -----&gt; daily precip files from 1950 to 2012)</div><div>set t 1</div><div>define rrdec=sum(rr,time=1dec2009,time=31dec2009)</div>


<div>open wrfprs_d01_744.ctl                                              -------&gt; month precip for dec 2009</div><div>set lat 34 48</div><div>set lon -16 -2</div><div>set t 1</div><div>define d=apcpsfc.2-rrdec</div>
<div><br></div><div>EOBS q ctlinfo</div><div>--------------------------------------------------</div><div><div>dset <a href="http://eobs_rr.nc" target="_blank">eobs_rr.nc</a></div><div>title                                                                                                                                                       </div>


<div>undef -9.99e+33                                                                                                                                             </div><div>dtype netcdf                                                                                                                                                </div>


<div>xdef 464 linear -40.375 0.25                                                                                                                                </div><div>ydef 201 linear 25.375 0.25                                                                                                                                 </div>


<div>zdef 1 linear 0 1                                                                                                                                           </div><div>tdef 23011 linear 00Z01JAN1950 1440mn                                                                                                                       </div>


<div>vars 1                                                                                                                                                      </div><div>rr=&gt;rr  0  t,y,x  rainfall                                                                                                                                  </div>


<div>endvars</div><div><br></div><div><br></div></div><div>WRF description file</div><div>------------------------------------------------------------------------------------------------------------------------</div>
<div><div>dset ^wrfprs_d01.744</div><div>index ^wrfprs_d01.744.idx</div><div>undef 9.999E+20</div><div>title wrfprs_d01.744</div><div>*  produced by grib2ctl v0.9.12.6</div><div>dtype grib 255</div><div>pdef 59 72 lccr 33.253000 -17.031000 1 1 41.500000 41.500000 -9.300000 25000 25000</div>


<div>xdef 59 linear -17.031000 0.271773636616826</div><div>ydef 72 linear 33.253000 0.227272727272727</div><div>tdef 2 linear 16Z10dec2009 512hr</div><div>*  z has 10 levels, for prs</div><div>zdef 10 levels</div><div>1000 875 750 625 500 375 250 125 30 2</div>


<div>vars 6</div><div>ACPCPsfc  0 63,1,0  ** surface Convective precipitation [kg/m^2]</div><div>APCPsfc  0 61,1,0  ** surface Total precipitation [kg/m^2]</div><div>NCPCPsfc  0 62,1,0  ** surface Large scale precipitation [kg/m^2]</div>


<div>PRATEsfc  0 59,1,0  ** surface Precipitation rate [kg/m^2/s]</div><div>REFD2mb  0 211,100,2 ** 2 mb Derived radar reflectivity [dbZ]</div><div>RWMRprs 10 170,100,0 ** (profile) Rain water mixing ratio [kg/kg]</div><div>


ENDVARS</div><div><br></div><div><br></div></div><div><br></div></div>