fixed division by zero in preloop and updated changelog

CHANGELOG.md

@@ -7,6 +7,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 ## [Unreleased]
 
 ### changed
+- **14_yields** fix division by zero in preloop of managementcalib_aug19
 - **22_land_conservation and default.cfg** Added options for baseline protection
 - **15_food, default.cfg and scenario_config.csv** changed fader setup and introduced new switches for specifying food substitution scenarios and exogeneous food intake scenarios
 - **70_livestock, default.cfg and scenario_config.csv** changed fader setup and introduced new switches for specifying feed substitution with SCP scenarios

modules/14_yields/managementcalib_aug19/preloop.gms

@@ -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)) *