Fwd: Re: [Proj] PROJ 4.5.0 beta (and Krovak!)

[Frank Warmerdam]

Gerald I. Evenden wrote:
 >Frank Warmerdam wrote:
>> warmerda at gdal2200[1926]% ./proj +proj=krovak +ellps=bessel
>> 10 45
>> -1164802.15     -1546506.69
>>
>> I don't really know any test points for Krovak or even what options
>> are required in the two implementations.
>>
>> For now, I'll stick with the existing Krovak code for the 4.5.0 release,
>> but if there are things we can do to make the two implementations
>> compatible with the aim of a seamless transition to use of libproj4
>> in the future, I'd be all for that!

Gerald I. Evenden wrote:
> I inserted the 10 45 number into an old script:
> 
> #!/bin/sh
> # This is a test script to check the correct execution
> # of the Krovak projection
> cat <<EOF >temp
> 35d42'35.2147 48d7'46.2973
> 10 45
> EOF
> echo "forward projection\n"
> ../lproj +proj=kocc +ellps=bessel +czech temp \
>      +lon_0=42d30 +lat_0=49d30 \
>      +lat_t=59d42\'42.69689 +lat_1=78d30 +k_0=.9999
> ../lproj +proj=kocc +ellps=bessel +czech -o temp \
>      +lon_0=42d30 +lat_0=49d30 \
>      +lat_t=59d42\'42.69689 +lat_1=78d30 +k_0=.9999 \
> 
> | ../lproj -I +proj=kocc +ellps=bessel +czech -i \
> 
>      +lon_0=42d30 +lat_0=49d30 \
>      +lat_t=59d42\'42.69689 +lat_1=78d30 +k_0=.9999 -W6
> #
> echo "above should agree with input of\n"
> cat temp
> rm temp
> 
> which produces the results:
> 
> forward projection\n
> -16643462.09	2422822.35
> -15043707.84	7571503.40
> 35d42'35.214700"E	48d07'46.297300"N
> 10d00'00.000000"E	45d00'00.000000"N
> above should agree with input of\n
> 35d42'35.2147 48d7'46.2973
> 10 45

Gerald,

OK, this leaves me with the impression that the PJ_krovak.c that was
contributed to me includes built in defaults that are compatible with
common use in the Czech Republic while, perhaps, yours (kocc) uses standard
defaults (ie. lon_0=0, lat_0=0, lat_t=0, lat_1=0?)

Do you have a suggestion on how we can align the two implementations so they
work the same from the commandline?

Best regards,
-- 
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I set the clouds in motion - turn up   | Frank Warmerdam, warmerdam at pobox.com
light and sound - activate the windows | http://pobox.com/~warmerdam
and watch the world go round - Rush    | President OSGeo, http://osgeo.org