add assert to trap error

src/camr.cc

@@ -332,7 +332,10 @@ template <class T> int CAmr::loadData(uns::CParticles<T> * particles,
             for (int ind=0;ind<twotondim;ind++) {
               for (int ivar=0; ivar<nvarg; ivar++) {
                 if (j==icpu&& ngrida>0) {
-                  grav.readDataBlock((char *) &varg[ivar*ngrida*twotondim+ind*ngrida]);
+                  int n=grav.readDataBlock((char *) &varg[ivar*ngrida*twotondim+ind*ngrida]);
+                  //std::cerr << "n="<<n<<"\n";
+                  assert(n==ngrida*8);
+
                 }
                 else grav.skipBlock();
               }