[Proj] Lat-Long to Lambert Conformal Conic(2SP) transformation inaccuracy issue

Oscar van Vlijmen ovv at hetnet.nl
Mon Feb 19 04:30:09 EST 2007


> From: Tonu Lukk
> Date: Sun, 18 Feb 2007 19:49:01 +0200
> Subject: Re: [Proj] Lat-Long to Lambert Conformal Conic(2SP) transformation
> inaccuracy issue

> Yet I still can't figure out why the +lat_0=57d31\'03.19415\"N
> gets interpereted wrong so that I end up with northing value approx. 98
> meters off the correct value.

Like I tried to convey:
some compilers, some operating system services can have a mind of their own.
As soon as a ' or " is encountered, the input or part of the input can be
interpreted as a string with numerical value zero.
As soon as for instance a \ or / or : is encountered, the input or part of
the input can be seen as illegal because some characters are reserved for
file path names.
This behavior could result in:
+lat_0=57d31\'03.19415\"N
being interpreted as
+lat_0=57d31
Try again with a value that cannot be attributed to rounding, like
+lat_0=57d31\'49.29\"N
If this produces the same result as
+lat_0=57d31
Then you know my theory could be true.
Solution: do not use illegal characters in the input.





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