r0                 53 src/grid_deformation.cpp   const double r_end = 2., r0 = 1., k = .5; // logistic function parameter
r0                 54 src/grid_deformation.cpp   const double r = r_end * r0 / (r_end*exp(-k*t) + r0*(1-exp(-k*t)));
r0                 61 src/secOrd_op_initData_impl.cpp   const double r0 = 1., r_end = 2., kt = .5 * t;
r0                 62 src/secOrd_op_initData_impl.cpp   return r0 / (r_end * exp(-kt) + r0 * (1 - exp(-kt)) );