Merge pull request #679 from DavidhoPIK/fix-division-by-zero-in-yield…

…-calibration

Fix division by zero in yield calibration preloop

CHANGELOG.md

@@ -50,6 +50,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - **35_natveg** removed growing stock calculation and calibration, which is no longer needed.
 
 ### fixed
+- **14_yields** fix division by zero in preloop of managementcalib_aug19
 - **extra/disaggregation** fixed bug in disaggregation of land conservation related to switch from 59k to 67k that produced erroneous outputs
 - **44_biodiversity** avoid division by zero
 - **scenario_config.csv** same revision for input files as in default.cfg

modules/14_yields/managementcalib_aug19/preloop.gms

@@ -59,9 +59,9 @@ i14_croparea_total(t_all,w,j) = sum(kcr, fm_croparea(t_all,j,w,kcr));
 
 i14_modeled_yields_hist(t_past,i,knbe14)
    = (sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14) * f14_yields(t_past,j,knbe14,w)) /
-      sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14)))$(sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14))>0)
+      sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14)))$(sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14))>0.00001)
    + (sum((cell(i,j),w), i14_croparea_total(t_past,w,j) * f14_yields(t_past,j,knbe14,w)) /
-      sum((cell(i,j),w), i14_croparea_total(t_past,w,j)))$(sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14))=0);
+      sum((cell(i,j),w), i14_croparea_total(t_past,w,j)))$(sum((cell(i,j),w), fm_croparea(t_past,j,w,knbe14))<0.00001);
 
 
 *' The factor `i14_lambda_yields` is calculated for the initial time step depending
@@ -127,9 +127,9 @@ if ((s14_calib_ir2rf = 1),
 * Calibrate newly calibrated yields to FAO yields
   i14_modeled_yields_hist2(i,knbe14)
    = (sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14) * i14_yields_calib("y1995",j,knbe14,w)) /
-      sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14)))$(sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14))>0)
+      sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14)))$(sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14))>0.00001)
    + (sum((cell(i,j),w), i14_croparea_total("y1995",w,j) * f14_yields("y1995",j,knbe14,w)) /
-      sum((cell(i,j),w), i14_croparea_total("y1995",w,j)))$(sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14))=0);
+      sum((cell(i,j),w), i14_croparea_total("y1995",w,j)))$(sum((cell(i,j),w), fm_croparea("y1995",j,w,knbe14))<0.00001);
 
   i14_yields_calib(t,j,knbe14,w) = sum((cell(i,j)), i14_fao_yields_hist("y1995",i,knbe14) /
                                                       i14_modeled_yields_hist2(i,knbe14)) *