Changes between Version 19 and Version 20 of GenParms

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Timestamp:
05/10/11 10:46:01 (2 years ago)
Author:
warmerdam
Comment:

notes on unit defaults.

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  • GenParms

    v19 v20  
    132132== Units == 
    133133 
    134 Horizontal units can be specified using the +units= keyword with a symbolic name for a unit (ie. us-ft).  Alternatively the translation to meters can be specified with the +to_meter keyword (ie. 0.304800609601219 for US feet).  The -lu argument to cs2cs or proj can be used to list symbolic unit names.  
     134Horizontal units can be specified using the +units= keyword with a symbolic name for a unit (ie. us-ft).  Alternatively the translation to meters can be specified with the +to_meter keyword (ie. 0.304800609601219 for US feet).  The -lu argument to cs2cs or proj can be used to list symbolic unit names.  The default unit is meters.  
    135135 
    136136== Vertical Units == 
    137137 
    138 Vertical (Z) units can be specified using the +vunits= keyword with a symbolic name for a unit (ie. us-ft).  Alternatively the translation to meters can be specified with the +vto_meter keyword (ie. 0.304800609601219 for US feet).  The -lu argument to cs2cs or proj can be used to list symbolic unit names.  
     138Vertical (Z) units can be specified using the +vunits= keyword with a symbolic name for a unit (ie. us-ft).  Alternatively the translation to meters can be specified with the +vto_meter keyword (ie. 0.304800609601219 for US feet).  The -lu argument to cs2cs or proj can be used to list symbolic unit names.  If no vertical units are specified, the vertical units will default to be the same as the horizontal coordinates. 
    139139 
    140140Note that vertical unit transformations are only supported in pj_transform() and programs built on that such as cs2cs.  The low level projections functions pj_fwd() and pj_inv() and programs using them directly such as proj do not handle vertical units at all.