)]}'
{
  "commit": "a406b17d66d90b26033331857f82eb2116795641",
  "tree": "c3acb63ac3046f75f4d0bb29cc9e84e489c54343",
  "parents": [
    "ca0ff62ddb8763e0f0f1a3e92dafd1bf24f34166"
  ],
  "author": {
    "name": "Sameer Agarwal",
    "email": "sameeragarwal@google.com",
    "time": "Sat Aug 18 15:28:49 2012 -0700"
  },
  "committer": {
    "name": "Sameer Agarwal",
    "email": "sameeragarwal@google.com",
    "time": "Tue Sep 04 10:35:23 2012 -0700"
  },
  "message": "Fix the jacobian scaling bug.\n\nIf the norm of a column in the jacobian is near zero.\nThe jacobian scaling could in trying to avoid division\nby zero actually make things much worse. It made it\nappear that the column actually had mass when in fact\nit did not.\n\nThis leads to inflated values for the parameters for\nthat column when we get some numerical garbage back\nfrom the linear solver.\n\nThis should also address the case where users are setting\nsome columns to zero to hold some parameter constant.\n\nThe fix is a bit delicate, and frankly I am not\ncompletely sure that it fixes the issue. But right now\nI am quite certain that the current implementation is\nbetter than what we had earlier. Whether this is the\nbest fix is not entirely certain.\n\nTo test the fix, I converted Arnaud Gelas\u0027 original\ncode which triggered this bug into a test case.\n\nChange-Id: Idbbd8177269bdc06338e0f54410f93ddc127c8ca\n",
  "tree_diff": [
    {
      "type": "modify",
      "old_id": "76c4f8a75806ea52d39b4c452a7ca7b5c3157e59",
      "old_mode": 33188,
      "old_path": "internal/ceres/trust_region_minimizer.cc",
      "new_id": "194d54ea8ec3e109c6a083fb643b202da8ad0bdd",
      "new_mode": 33188,
      "new_path": "internal/ceres/trust_region_minimizer.cc"
    },
    {
      "type": "modify",
      "old_id": "414567a73b4cd3cdb806a1140787fb81b338910e",
      "old_mode": 33188,
      "old_path": "internal/ceres/trust_region_minimizer_test.cc",
      "new_id": "9d5af1aa8d7b73c18199c4bfc800d70c56827aae",
      "new_mode": 33188,
      "new_path": "internal/ceres/trust_region_minimizer_test.cc"
    }
  ]
}