--- In guide-user@yahoogroups.com, "vgardiner" <vgardiner@...> wrote:

>
> I will ask once again.
> How do I organise Guide8 to have the ability to allow a
> 'Goto' to a WDS name.
> Surely some of you people are able to do it?

Woah! Raw nerves, there.

Alright, there're several aspects to this.

If you are using the internal stuff off of the CDROM you use GOTO Double Star and then follow dialogue boxes around.

If you are using a TDF route there is not a simple answer because there are several incarnations aruond in different distros. WDS 1998? WDS 2001.5 (sometimes just called 2001), WDS 2006.5?

So I'll give you the basic logic of how it works in TDFs and the rest you'll have to ascertain for yourself.

First, you will have to know which TDF you are using, it will be in your Guide directory. Whether it is called WDS.tdf or something else I have no idea of knowing.

Back it up just in case.

Use and ascii or text reader and make sure Guide isn't running as there is a possibility of opening some files more than once without any "file already open" messages at times and this can cause file corruption. It's very rare (I've done it once by accident coz I used a very old DOS ascii reader) but it's possible.

Now, read down your TDF. There's file name and title name and RA and Dec instructions, then probably a mag line.

The line you are interested in will be soon after these and it reads

text c l

where c is any number and is the start column and l is any length, and it means the number of columns following on from there.

mine's 11 13 for instance, start column 11, 13 columns long (inclusive).

Now you go back to the first line that says file which points towards the data file that is being used by this TDF, you go to that file and you look at what lives in those columns.

Basically, it is this.

text is the line that tells the labels what to write.

Later in the TDF there can be a command called "pref" for prefix, so you can add a prefix to the label if needed, it it's a repeat word, like GSC or 3UCAC or something. But text tells the LABEL what to print.

And you go to the MENU and GOTO and TDF and up pops the TDF list and you click on the WDS catalogue you want and in the dialogue box you type the name you are looking for...

...but double star discovery names are a bit of a mixed bunch.

Several rows can represent the same name. DBL 1AB and DBL 1CD for instance would still be DBL 1.

Some _sometimes_ a TDF is long enough to cover all those options.

Now in WDS you will also get things like DBL 2

No A or B.

So what I have is enough columns after text to cover all eventualities.

We have a small side issue now.

Near the bottom of the TDF, amongs words like 'field' and 'sort' and 'type' there should be these commands

label spaces
goto spaces
goto case

these are for the GOTO TDF. Many catalogues have numbered objects, and if say 1 to 1000 objects the 1 will be preceded by three SPACE characters, so things line up re numbers, eg

1
1001

that sort of thing. LABEL SPACES says ignore extra spaces, so you don't have to be pedantic when you enter the search number and type

1

as

1

will do.

Actually, LABEL spaces is likely for the LABEL, GOTO SPACES is probably the one I mean for GOTO.

And GOTO case is probably self explanatory, ie, ignore CASE when searching, so if you look for STF 1 you can type stf 1 .

And that's how it all hooks together. But because I sometimes don't want the primary pair, and the binary might be quite wide, I have my WDS TDF set up to include AB and BC and such, so if there are blank spaces following the TDF

DBL 2

then I just have to GOTO -> TDF -> WDS -> dbl 2

WDS usually doesn't bother putting AB unless the star is triple or multiple.

If multiple then it's be GOTO -> TDF -> WDS -> dbl 1ac for instance.

So you have to look at your tdf and what it is using in the data for GOTO to see why a GOTO TDF works in some cases and not others for some datasets. It is usually only weird cases like old style catalogues that follow more mixed and complex names, and instead of having a unique name for every object in the list, ie one system per row to avoid confusion, has the same name several times with A, B, c etc stuck after it.

NOW, having said all that, and even allowing for all that, goto tdf wds doesn't work every single time, even if you follow all the rules.

Why not? Probably some little buggette that only crops up in WDS.

Something else about GOTO TDF. You are searching on the columns oulined in the command

text

these are not sorted. WDS will be sorted on RA. So Guide goes through all the string column, of the entire dataset, which is over 100,000 rows in WDS, looking for your exact string request (spare space characters dropped) because unlike with the RA it can't jump along in a sorted file nor stop when it has searched all the words beginning with d for dbl, for an example, as it is not alphabetially sorted on discoverer name, but is sorted on RA for very quick plotting. And tt seems sometimes it cannot find them.

I've never seen this happen with any other dataset or TDF. Only WDS. Therefore it is not highlighted and rarely crops up as a problem.

The main thing everyone has to remember, not just yourself, about astronomical data is that sometimes the data has problems. Often the data is screwed in some way or other. Sometimes because it's because on old style card index format has been shoehorned into an electronic file. If this classic catalogue was being generated today it like wouldn't be databased that way, but it inherits the old book and card index format, mostly because it was one of the first catalogues to be placed into electronic form (the IDS, the WDS precursor, was actually put on computer punch card in the sixties!).

No matter how good Guide or whatever software works, some data will just be intractable in certain respects. It's like when folk post here and say "why has Guide said this, why has Guide done this wrong". Guide has merely coughed up what the data has told it to cough up, and done it well enough the vast majority of the time. If the data is "problematic", well, that's the data's problem.

Summary : goto tdf uses the columns delineated in the relevant TDF by the line TEXT, which is also used to give the core of labels. Checking this extent and examining various entries in the relevant columns of the relevant data file lets the user know the full diversity and nuances of 'names' living in those columns. The name may not be the sorted column, so this will slow the search for big files in those instances. GOTO SPACES and GOTO CASE in the TDF will allow for ignoring spare space characters and/or whether upper or lower case is being used in the data file. Yet in some instances it still falls over. Whether this is an obscure bug in Guide that's rarely seen or some other nuisance of the data file is not always clear. For instance, some "spaces" in some data files are not SPACE characters but other codes, possibly even TAB characters. This latter too can cause problems for string identification, in software other than Guide too.

FIX : set text to cover the WDS identifier instead of the discovery identifier, and then search on that instead. However, you will not like this solution because the probability is great that the likely way for your identifying the WDS identifier is to look it up in Guide using the discovery identifier... ...sometimes data will do that to you.

Cheers

John