[GRASS-dev] [GRASS GIS] #3052: Watts to MegaJoules/Day conversion issue

[GRASS GIS]

#3052: Watts to MegaJoules/Day conversion issue
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 Reporter:  cholmes  |      Owner:  grass-dev@…
     Type:  defect   |     Status:  new
 Priority:  normal   |  Milestone:  7.0.5
Component:  Default  |    Version:  unspecified
 Keywords:           |        CPU:  Unspecified
 Platform:  All      |
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 I think I may have found an error in a few files from the grass-ci repo.

 A few files:

 https://github.com/GRASS-GIS/grass-
 ci/blob/f1a15d967611006e920b8dc2f191391e44392019/imagery/i.evapo.mh/mh_eto.c#L15
 https://github.com/GRASS-GIS/grass-
 ci/blob/f1a15d967611006e920b8dc2f191391e44392019/imagery/i.evapo.mh/mh_original.c#L14
 https://github.com/GRASS-GIS/grass-
 ci/blob/f1a15d967611006e920b8dc2f191391e44392019/imagery/i.evapo.mh/mh_samani.c#L14

 contain a line like:


 {{{
 ra = ra * (84600.0 * 1000.0);   /*convert W -> MJ/d */
 }}}


 I'm guessing the magic constant 84600 is intended to be the number of
 seconds in a day, which is actually 86400. Also, Watts * Seconds gives
 Joules. If you intend to get MegaJoules, you must divide by 1000, not
 multiply (but maybe the comment is just wrong, and you wanted
 milliJoules?).

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Ticket URL: <http://trac.osgeo.org/grass/ticket/3052>
GRASS GIS <https://grass.osgeo.org>