Remove ParameterBlock::state_offset as it is not used.

Change-Id: I3d6fbe333dde73ceb4c6c5e01460aa997883889f

internal/ceres/parameter_block.h

diff --git a/internal/ceres/parameter_block.h b/internal/ceres/parameter_block.h
index f20805c..dd69cd6 100644
--- a/internal/ceres/parameter_block.h
+++ b/internal/ceres/parameter_block.h
@@ -112,10 +112,6 @@
   int index() const { return index_; }
   void set_index(int index) { index_ = index; }
 
-  // This parameter offset inside a larger state vector.
-  int state_offset() const { return state_offset_; }
-  void set_state_offset(int state_offset) { state_offset_ = state_offset; }
-
   // This parameter offset inside a larger delta vector.
   int delta_offset() const { return delta_offset_; }
   void set_delta_offset(int delta_offset) { delta_offset_ = delta_offset; }
@@ -176,14 +172,13 @@
 
   string ToString() const {
     return StringPrintf("{ user_state=%p, state=%p, size=%d, "
-                        "constant=%d, index=%d, state_offset=%d, "
+                        "constant=%d, index=%d, "
                         "delta_offset=%d }",
                         user_state_,
                         state_,
                         size_,
                         is_constant_,
                         index_,
-                        state_offset_,
                         delta_offset_);
   }
 
@@ -202,7 +197,6 @@
     }
 
     index_ = -1;
-    state_offset_ = -1;
     delta_offset_ = -1;
   }
 
@@ -255,9 +249,6 @@
   // permit switching from a ParameterBlock* to an index in another array.
   int32 index_;
 
-  // The offset of this parameter block inside a larger state vector.
-  int32 state_offset_;
-
   // The offset of this parameter block inside a larger delta vector.
   int32 delta_offset_;
 

internal/ceres/program.cc

diff --git a/internal/ceres/program.cc b/internal/ceres/program.cc
index 82d76d3..99f6af9 100644
--- a/internal/ceres/program.cc
+++ b/internal/ceres/program.cc
@@ -129,13 +129,10 @@
     }
   }
   // For parameters that appear in the program, set their position and offset.
-  int state_offset = 0;
   int delta_offset = 0;
   for (int i = 0; i < parameter_blocks_.size(); ++i) {
     parameter_blocks_[i]->set_index(i);
-    parameter_blocks_[i]->set_state_offset(state_offset);
     parameter_blocks_[i]->set_delta_offset(delta_offset);
-    state_offset += parameter_blocks_[i]->Size();
     delta_offset += parameter_blocks_[i]->LocalSize();
   }
 }

internal/ceres/solver_impl.cc

diff --git a/internal/ceres/solver_impl.cc b/internal/ceres/solver_impl.cc
index e16b6a0..c45c194 100644
--- a/internal/ceres/solver_impl.cc
+++ b/internal/ceres/solver_impl.cc
@@ -733,7 +733,7 @@
     linear_solver_options.elimination_groups.push_back(it->second.size());
   }
   // Schur type solvers, expect at least two elimination groups. If
-  // there is only one elimination group, then CreateReducedProblem
+  // there is only one elimination group, then CreateReducedProgram
   // guarantees that this group only contains e_blocks. Thus we add a
   // dummy elimination group with zero blocks in it.
   if (IsSchurType(linear_solver_options.type) &&