[Proj] proj.4 problems

Frank Willett fyw at wwwtools.com
Fri Nov 25 19:41:58 PST 2011


Hi All,

I have been testing proj.4 version 4.7.0 and have a few problems. I thought
I would submit them to the mailing list first for comments before submitting
them as bugs. Please let me know if you have a solution to any of these that
do not require modifying the source code.

For the problems at the origin, I ran the problem at 0,0 and 1,1 which is one
unit offset in X and Y.

aitoff - aitoff projection says it has an inverse but it doesn't.
         Modified pj_aitoff.c to set no inv.
         
alsk - Compute LL from XY is wrong at the origin long/lat (-152,64)
       $ proj +proj=alsk -I
       >0 0
       56dE    64dN
       >1 1
       151d59'59.926"W 64d0'0.032"N
         

gs48 - 1) The origin of the projection is at long/lat -96,-39 and it should
          be at -96,+39
          Modified pj_mod_ster.c to change the sign on phi0 for the gs48 projection
          2) Origin problem
          $ proj +proj=gs48  -I
          >0 0
          168dE   39dN
          >1 1
          95d59'59.958"W  39d11'17.79"N

gs50 - Origin problem
       $ proj +proj=gs50 -I
       >0 0
       120dE   45dN
       >1 1
       119d59'59.954"W 45d0'0.033"N
       
imw_p - Origin problem
        $ proj +proj=imw_p +lat_1=2 +lat_2=6 +lon_1=0 -I
        >0 0
        -2147483648d-2147483648'nan"E   -2147483648d-2147483648'nan"N
        >1 1
        0d0'0.032"E     2d0'0.033"N             
       
lee_os - 1) Got an email that the value of A is wrong 
                Changed from -0.0088162 to -0.00881625 (more accuracy)
            2) Origin problem
            $ proj +proj=lee_os -I
            >0 0
            30dE    10dS
            >1 1
            164d59'59.954"W 10d3'57.623"S         
                
mil_os - Origin problem.
         $ proj +proj=mil_os -I
         >0 0
         40dE    18dN
         >1 1
         20d0'0.037"E    18d6'48.274"N  
         

pconic - Origin problem.
         $ proj +proj=pconic +lat_1=0 +lat_2=10
         >0 0
         0.00    555891.27

         $ proj +proj=pconic +lat_1=0 +lat_2=10 -I
         >0 0
         0dE     0dS
         >0 555891.27
         0dE     5dN           
               
putp3p - Has the no inv. flag set but the inverse does exist
             Removed the no inv. flag from putp3p .. inverse seems to work
         
tissot - Origin problem
         $ proj +proj=tissot +lat_1=0 +lat_2=10
         >0 0
         0.00    -139902.82

         $ proj +proj=tissot +lat_1=0 +lat_2=10 -I
         >0 0
         0dE     1d15'24.366"N
         >0 -139902.82
         0dE     0dN         

wintri - wintri projection says it has an inverse but it doesn't.
         Modified pj_aitoff.c to set no inv.
         
 Frank Willett (fyw at wwwtools.com)
        


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