diff options
| -rw-r--r-- | docs/source/apps/gie.rst | 20 | ||||
| -rw-r--r-- | src/gie.c | 26 |
2 files changed, 43 insertions, 3 deletions
diff --git a/docs/source/apps/gie.rst b/docs/source/apps/gie.rst index b6c1c166..b3d1a06b 100644 --- a/docs/source/apps/gie.rst +++ b/docs/source/apps/gie.rst @@ -207,10 +207,26 @@ gie command language to function. The accepted coordinate is passed to the operation first in it's forward mode, then the output from the forward operation is passed back to the inverse operation. This procedure is done ``n`` times. If the - resulting coordinate is within the set tolerance of the initial coordinate + resulting coordinate is within the set tolerance of the initial coordinate, the test is passed. - Example: + Example with the default 100 iterations and the default tolerance: + + .. code-block:: console + + operation proj=merc + accept 12 55 + roundtrip + + Example with count and default tolerance: + + .. code-block:: console + + operation proj=merc + accept 12 55 + roundtrip 10000 + + Example with count and tolerance: .. code-block:: console @@ -705,6 +705,20 @@ static int roundtrip (const char *args) { /***************************************************************************** Check how far we go from the ACCEPTed point when doing successive back/forward transformation pairs. + +Without args, roundtrip defaults to 100 iterations: + + roundtrip + +With one arg, roundtrip will default to a tolerance of T.tolerance: + + roundtrip ntrips + +With two args: + + roundtrip ntrips tolerance + +Always returns 0. ******************************************************************************/ int ntrips; double d, r, ans; @@ -719,7 +733,17 @@ back/forward transformation pairs. } ans = proj_strtod (args, &endp); - ntrips = (int) (endp==args? 100: fabs(ans)); + if (endp==args) { + /* Default to 100 iterations if not args. */ + ntrips = 100; + } else { + if (ans < 1.0 || ans > 1000000.0) { + errmsg (2, "Invalid number of roundtrips: %lf\n", ans); + return another_failing_roundtrip (); + } + ntrips = (int)ans; + } + d = strtod_scaled (endp, 1); d = d==HUGE_VAL? T.tolerance: d; |