On 1/10/2012 16:41, Sven Barth wrote:
On 10.01.2012 22:02, waldo kitty wrote:
hummm... i may not need this specialization, then... i'm not comparing
the entire record but portions of the fields in the records... i've made
a few changes that should make this easier for me to do... let me show
an example of an input record...
It's not about YOU comparing the entire record. The TFPGList uses that
internally for it's own bookkeeping.
ahhh!
The specialization is mostly for type safety and ease of use. As I show you
below a simple pointer based TList works as well (if you follow some advices).
In the end it should be easier to handle than an array ;)
i never did like pointers... hard to wrap my head around what was what and how
to access certain things... but then again, i'm self-taught ;)
ISS (Zarya)
1 25544U 98067A 11355.91136867 .00021672 00000-0 28116-3 0 6701
2 25544 51.6441 296.4760 0024445 190.7247 276.2995 15.58432251750217
this breaks out like this...
line columns example description
0 1-24 ISS (Zarya) common name
1 1 1 element line number
1 3-7 25545 catalog number
1 8 U elset classification
1 10-17 98067A international designator
1 19-32 11355.91136867 epoch (UTC)
1 34-43 .00021672 1st deriv of mean motion
1 45-52 00000-0 2nd deriv of mean motion
1 54-61 28116-3 B* drag term
1 63 0 element set type
1 65-68 670 element number
1 69 1 checksum
2 1 2 element line number
2 3-7 25545 catalog number
2 9-16 51.6441 orbit inclination
2 18-25 296.4760 rt ascension acend node
2 27-33 0024445 eccentricity
2 35-42 190.7247 arg of perigee (degrees)
2 44-51 276.2995 mean anomaly (degrees)
2 53-63 15.58432251 mean motion (revs/day)
2 64-68 75021 rev number at epoch
2 69 3 checksum
so i now have the following to define the record... since i only need
the catalog number to check for duplicates and the epoch to determine
which one to keep, i've added those two fields to the record and pull
them during the reading of the data (see Input_Satellite_List procedure
below)...
Wouldn't it be easier for you to parse the complete two lines into a full blown
record (just asking).
in the future, i will want to do this... however, this tool is a first step into
mangling^H^H^H^H^H^Hssaging TLE data... the only purpose for this tool is to
merge TLE files together into one master file with /ALL/ available satellite
TLEs listed... the current old DOS program simply cannot do this due to memory
constraints... as such, i only need know the catalog number and the epoch of the
two... once the final sorted merged list is completed, it is all going to be
written back to a plain 7bit ascii text file like it all originated from... this
text file is then used for my other satellite and astronomy related applications ;)
Then you don't need to parse them later on and can just do
a "YourRecord.MeanAnomaly" (for example). Using a TStringList with the correct
parameters can also remove the burden from you to seperate the values by hand.
at this time, this only needs be done with these two (sub)fields in the TLE
entries... i'm only interested in these two but am storing everything to make it
easier to later run thru the list or collection or array and write the three
original lines to a master TLE text file...
Function IsSameReal(num1,num2 : double) : integer;
begin
if (num1 < num2) then IsSameReal := -1
else
if (num1 = num2) then IsSameReal := 0
else
if (num1 > num2) then IsSameReal := 1;
end;
You can shorten this by using the "CompareValue" function from unit "Math":
function IsSameReal(num1,num2: Double): Integer;
begin
IsSameReal := CompareValue(num1, num2);
end;
interesting! in fact, i don't really even need "IsSameReal" as i can simply use
CompareValue directly with these two numbers?
(though I would name that function CompareReal instead of IsSameReal ;) )
hahaha! true :)
something else i need to make sure of is that this will compile on my
OS/2 FPC 2.4.2 since that is the environment it will be under when it
goes production... unless, of course, there's a shiney new
0s2260full.zip file for me to play with ;)
[...]
as i wrote in another message, my windows' boxen update from SVN and
every time i've tried to update FPC and make whatever, it breaks and i'm
scared to break what i currently have working... i always have to blow
the directory away, then svn it all back down, and then do the make
thing... the ugly part is that i also have lazarus built with and using
this svn'd version of FPC so i definitely do not want to be breaking
that, either...
a second reason is i don't do the svn thing on the OS/2 box and so have
to rely on an install package for that OS... the last time i did this, i
unzipped os2242full.zip to /fpc and went from there... i recall having
to manually configure a lot of stuff, though... include paths and the
like... i still don't have the help working properly in any environment
which greatly hampers things :/
You'll need to ask Tomas Hajny then as he is the one who is most familiar with
OS/2. But there seems to indeed be a os2260full.zip at SourceForge :) (So it
might be worthwhile to investigate in an update, not only because of generics
;) )
it is something i'll have to play with... my windows' boxen should be all set
for me to pick and choose which FPC version i use... i've not (yet) done similar
for lazarus but that's for another place ;)
2. You can then use the TList which is based on pointers (and requires
a bit
manual housekeeping, but I can help you here as well if you want)
TList? hummm... better? smaller? faster? easier to use? small memory
footprint? i'm game to try things as long as it works in the end ;)
TList is basically an array wrapped in a class (though I would suggest TFPList
as that is faster than TList (TList is based on TFPList)). Both can be found in
unit Classes.
ok... this is another one of the several possible solutions i've been looking
at... uncle google has been showing me a lot but i don't seem to find much that
has a decent example that's close enough to my needs to whack it into submission...
The following you need to know: T(FP)List works on pointers, thus you need to
1. declare a pointer type to your record type (e.g. Pthree_line_data =
^three_line_data)
2. allocate a Pthree_line_data variable if you want to add a new entry to the
list
this looks vaguely similar to what i did in TP/BP with a TSortedCollection which
built a sorted list of paths that messages took during their transit from the
originating machine to my machine... those paths were all numeric and there was
only one path per "record" so it was much easier to work with than what i'm
flailing about with now...
[TRIM]
5. At the end of the list's lifetime you need to Dispose all items (or before
you clear the list)
E.g.
for i := 0 to aList.Count - 1 do
Dispose(Pthree_line_data(aList[i]));
aList.Clear; // or aList.Free depending on the context
I hope this helps you along, but feel free to ask more if you need help. :)
this is looking kinda familiar, really... the last time i did this, ie: the
message path program mentioned above, i went on "vacation" to the mountains and
spent the whole 7 days holed up with my pascal books, a computer, and a lot of
sample data to work with... i did get the task accomplished but never really got
to enjoy my "vacation in the mountains"... at least not more than simply getting
away where there were no distractions...
"i'll be bach" :P
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