[GRASS-dev] [GRASS GIS] #1575: r.horizon bugfix and speedup

[GRASS GIS]

#1575: r.horizon bugfix and speedup
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 Reporter:  sprice       |       Owner:  grass-dev@…              
     Type:  enhancement  |      Status:  new                      
 Priority:  normal       |   Milestone:  7.0.0                    
Component:  Raster       |     Version:  svn-trunk                
 Keywords:  r.horizon    |    Platform:  All                      
      Cpu:  All          |  
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Comment(by hamish):

 Hi,

 C Q: is declaring variables mid-function (say at the start of an if(){}
 statement) fully portable to all the platforms/compilers that we wish to
 support? how about declaring and initializing variables at the same time?
 +/-'s?

 does the /100 -> *0.01 remove the expensive divide op, or is it just about
 removing the cumulative number of ops?

 is declaring a new variable relatively inexpensive vs declaring it then
 using it?

 which part of the patch specifically is the bug?


 (as concerned with readability/maintainability as I am with speed; w/ code
 comments where appropriate we can have the best of both worlds; the "Code
 folded into the 'if' statement:" explanation is great tx)


 thanks,
 educational-mode non-comp.sci. major Hamish

 ps- in general I think we can gain a huge amount from running various bits
 of grass through a profiler. the "Bugs" wiki page has some suggestions,
 the yes,still-free-for-non-commercial/research-use Intel C compiler has a
 very good profiler+tutorial too.  thanks Seth!

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Ticket URL: <https://trac.osgeo.org/grass/ticket/1575#comment:4>
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