JPL DE with Pascal unit hns_uDE

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Asterix
Posts: 15
Joined: 06 Jun 2019, 16:00

JPL DE with Pascal unit hns_uDE

Post by Asterix » 13 Jul 2019, 15:01

Hello Han,

I try now to implement this unit in my program and have a question related to the input parameters of

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function load_de_file2(jd: double; path1:string; var jdstart,jdend: double): boolean;{load de file}
The selected DE423 files have been saved in a folder containing

...\423\ascp1800
...\423\ascp1850
...\423\ascp1900
...\423\ascp1950
...\423\ascp2000
...\423\header

The input parameters to the load-function are not clear, also because the script contains also the variable

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de_eph.ephem_step
My questions:
1) Is the jd the julian date and time of the planet positions to be calculated ?
2) Is path1 for the folder containing the ascp files, or is it for the first one (here ascp 1800) or is it to the applicable one for jd ?
3) Do jdstart and jdend relate to the applicable one related to jd, or do they relate to the available files in folder \423 ?
4) Relate jdstart and jdend to the annual range of all available files in this case start 1.1.1800 and end a 31.12.2049 ?
5) How does the program find the step size ?
and an other question
6) Would you expect somewhere a problem if all Double formats would be replaced by Extended ones ?
Somewhat later while trying to compile it
7) DateUtils ... is missing
8) bufi: pdouble ... pdouble is undefined

I would very much appreciate if you coud please provide some clarification on how to start loading the applicable DE-file.

Thanks and regards,
Marcel

Asterix
Posts: 15
Joined: 06 Jun 2019, 16:00

Re: JPL DE with Pascal unit hns_uDE

Post by Asterix » 16 Jul 2019, 16:14

Well, I could now at least compile the unit. It looks however like the FileStream is intended for a different input than the JPL ascii files which I offered to read. Your code does not seem to distinguish between the JPL's header file and its data files. Could it be that you read directly JPL's binary file or do you combine (manually) the relevant ascii files before reading them? Some clarifications would be very much appreciated.
Thanks and regards,
Marcel

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