adding code images

docs.it4i/software/viz/insitu.md

@@ -45,12 +45,19 @@ It will generate the CxxFullExampleAdaptor executable file. This can be later ru
 
 ## Code explanation
 
-Provided example is a simple MPI program. Main executing part is written in FEDriver.cxx. It is a simulator code that creates computational grid and performs simulation (see below). 
+Provided example is a simple MPI program. Main executing part is written in FEDriver.cxx. It is a simulator code that creates computational grid and performs simulation-adaptor interaction (see below). 
 
-Dimensions of the computational grid in terms of number of points in x, y, z direction are supplied as input parameters to the *main* function (see lines 22-24). The fourth parametr in *main* is for the name of a Python script (we use feslicescript.py) that sets up the ParaView-Catalyst pipeline. 
+Dimensions of the computational grid in terms of number of points in x, y, z direction are supplied as input parameters to the *main* function (see lines 22-24). Based on the number of MPI ranks each MPI process creates different part of the overall grid. The fourth parametr in *main* is for the name of a Python script (we use feslicescript.py) that sets up the ParaView-Catalyst pipeline. After the Adaptor initialization on line 36 we start the simulation by linearly progressing *timeStep* value in the *for* loop. Each iteration of the loop upates the grid attributes (Velocity and Pressure) by calling the UpdateFields method in Attributes class
+ 
+![](insitu/img/FEDriver.png "FEDriver.cxx")
 
 
-![](insitu/img/FEDriver.png "FEDriver.cxx")
+Within the UpdateFields method the velocity progresses with the value of *time* and with the specific value of *setting* which depends on the respective MPI rank. In this way, different processes can be visually distinguished during the simulation.   
+
+![](insitu/img/UpdateFields.png "UpdateFields method of the Attributes class")
+
+In each iteration of the simulation, adaptor's CoProcess function is called by using actual parameters of the grid in time.
+
 
 mpirun -n 2 ./CxxFullExample 30 30 30 ../SampleScripts/feslicescript.py 
 

docs.it4i/software/viz/insitu/FEAdaptor.cxx

@@ -145,7 +145,7 @@ void CoProcess(
   dataDescription->SetTimeData(time, timeStep);
   if (lastTimeStep == true)
   {
-    // assume that we want to all the pipelines to execute if it
+    // assume that we want to execute all the pipelines if it
     // is the last time step.
     dataDescription->ForceOutputOn();
   }

docs.it4i/software/viz/insitu/FEDataStructures.h

@@ -24,9 +24,8 @@ class Attributes
 {
   // A class for generating and storing point and cell fields.
   // Velocity is stored at the points and pressure is stored
-  // for the cells. The current velocity profile is for a
-  // shearing flow with U(y,t) = y*t, V = 0 and W = 0.
-  // Pressure is constant through the domain.
+  // for the cells.
+
 public:
   Attributes();
   void Initialize(Grid* grid);