Correct the random scaling on salt generation.

Enable high migration adjustment.

Author: highperformancecoder

models/ecolab_model.cc

@@ -636,7 +636,7 @@ void SpatialModel::generate(unsigned niter)
 unsigned SpatialModel::migrate()
 {
   /* each cell gets a distinct random salt value */
-  hostForAll([=,this](EcolabCell& c) {c.salt=c.rand();});
+  hostForAll([=,this](EcolabCell& c) {c.salt=Float(c.rand()-c.rand.min())/(c.rand.max()-c.rand.min());});
 
   prepareNeighbours();
 
@@ -660,37 +660,36 @@ unsigned SpatialModel::migrate()
         auto& nbr=*n->as<EcolabCell>();
         Float salt=c.id<nbr.id? c.salt: nbr.salt;
         array<Float> m=(tstep-last_mig_tstep) * migration * (nbr.density - c.density);
-        delta[c.idx()]+=m + array<Float>((m!=0.0)*(2*(m>0.0)-1)) * salt;
+        delta[c.idx()]+=m+ array<Float>((m!=0.0)*(2*(m>0.0)-1)) * salt;
       }
   });
 
   array<int> ssum(species.size(),0);
   size_t totalMigration=0;
   hostForAll([&,this](EcolabCell& c) {
-//    // adjust delta so that density remains +ve
-//    array<int> adjust=delta[c.idx()]+c.density;
-//    adjust*=-(adjust<0);
-//    if (sum(adjust)>0)
-//      {
-//        // distribute adjust among neighbours
-//        array<int> totalDiff(c.density.size(),0);
-//        for (auto& n: c)
-//          {
-//            auto& nbr=*n->as<EcolabCell>();
-//            totalDiff+=nbr.density-c.density;
-//          }
-//        // adjust adjust to be divisible by totalDiff
-//        adjust-=adjust%totalDiff;
-//        for (auto& n: c)
-//          {
-//            auto& nbr=*n->as<EcolabCell>();
-//            delta[nbr.idx()]+=((nbr.density-c.density)/totalDiff)*adjust;
-//          }
-//        delta[c.idx()]-=adjust;        
-//      }
-
-    //c.density+=delta[c.idx()];
-    cout<<delta[c.idx()]<<endl;
+    // adjust delta so that density remains +ve
+    array<int> adjust=delta[c.idx()]+c.density;
+    adjust*=-(adjust<0);
+    if (sum(adjust)>0)
+      {
+        // distribute adjust among neighbours
+        array<int> totalDiff(c.density.size(),0);
+        for (auto& n: c)
+          {
+            auto& nbr=*n->as<EcolabCell>();
+            totalDiff+=nbr.density-c.density;
+          }
+        // adjust adjust to be divisible by totalDiff
+        adjust-=adjust%totalDiff;
+        for (auto& n: c)
+          {
+            auto& nbr=*n->as<EcolabCell>();
+            delta[nbr.idx()]+=((nbr.density-c.density)/totalDiff)*adjust;
+          }
+        delta[c.idx()]-=adjust;        
+      }
+
+    c.density+=delta[c.idx()];
     totalMigration+=sum(abs(delta[c.idx()]));
 #if !defined(NDEBUG)
 #pragma omp critical

models/spatial_ecolab.py

@@ -13,7 +13,7 @@
 array_urand.seed(10+myid())
 
 # initial number of species
-nsp=100
+nsp=30
 
 ecolab.repro_min(-0.1)
 ecolab.repro_max(0.1)
@@ -28,8 +28,8 @@ def randomList(num, min, max):
 
 ecolab.species(range(nsp))
 
-numX=3
-numY=3
+numX=1
+numY=2
 ecolab.setGrid(numX,numY)
 ecolab.partitionObjects()
 
@@ -47,7 +47,7 @@ def randomList(num, min, max):
 ecolab.interaction.val(randomList(len(ecolab.interaction.val), ecolab.odiag_min(), ecolab.odiag_max()))
 
 ecolab.mutation(nsp*[ecolab.mut_max()])
-ecolab.migration(nsp*[1e-20])
+ecolab.migration(nsp*[1e-3])
 
 from plot import plot
 from GUI import gui, statusBar, windows
@@ -91,7 +91,6 @@ def step():
     for i in range(epoch//10000):
         stepImpl()
     if myid()==0:
-        print(migrations)
         nsp=len(ecolab.species)
         statusBar.configure(text=f't={ecolab.tstep()} nsp:{nsp}')
         plot('No. species',ecolab.tstep(),nsp,200*(ecolab.tstep()%epoch<0.5*epoch))