Celestia Forums

I downloaded the script from the ML and tried it out.
Now I am assuming that it works like you are standing on earth at the beginning of the script, correct?
So if I do the "enter-star name-enter-c" I should get it's RA, which i think is right. I typed in GAM Hya then "c" to center it
and it gave me a RA of 13h 18m 55.2s, looked it up on wikipedia and it said 13h 18m 55.3s, so I assume the script is right.
But the script gives a DEC of -23.17, where as wikipedia gives -23h 10m 18s.
So how do convert that -23.17 that the script gives to what Wikipedia gives?

Thanks,
Tim

You need a function to converts the hour decimal value to hour, min, sec:

Thanks you, but what do I do with this function? or where do I put it?

Tim

You can paste the hourToHourMinSec() function just below the deg2hms() function.

Then, change the following line (at the end of the script):

into:


That should do it.

Well I must have messed it up
Get this error now (see pic)
Also attached the script with the changes I made that you gave me.
Thank you for your help,
Tim

Hi Tim,

I have seen pics of many of your Star Trek add-ons, and they are awesome. I hope to see many more to come.

Regarding the Declination issue, here are a few notes for Vincent that may help.


Hi Vincent,

1) Since it's a Declination we're talking about, it should be given in ?, arc-minutes and arc-seconds, rather than in hours, minutes and seconds. I found this Wikipedia link to confiirm that they expressed it correctly. http://en.wikipedia.org/wiki/Gamma_Hydrae If it's expressed differently in another link, it's probably a mis-type.
2) Shouldn't you use math.abs() first when a Declination is negative? Lua's math.floor() function returns the integer "less than" a value given, so—since this Declination (-23.17) is negative—it runs into problems because math.floor( -23.17 ) should return -24. I always "save" the negative sign as a boolean, then use math.abs( ) before the conversion, then add the sign back to the degrees.

Here's my function that converts Decimal Degrees to Degrees, ArcMinutes and Arc-Seconds. The logic is essentially the same as in your code, except for the missing math.abs( ) function.



Hope it helps.

--Gary

Thank you
Now just to make sure I get this right .
I take this code-


And put in place of this code-


Thank you for help guys,
Tim

fungun wrote:Well I must have messed it up
Get this error now (see pic)

You need to remove the following line from your code:
This line was simply given as an example of how to call the hourToHourMinSec function.

VikingTechJPL wrote:1) Since it's a Declination we're talking about, it should be given in ?, arc-minutes and arc-seconds, rather than in hours, minutes and seconds.

Yes, sure. Tim should actually do the maths to convert the hour, min, sec wikipedia values into deg, arc-min, arc-sec.
I provided the hourToHourMinSec() function because he was asking for it, though.

VikingTechJPL wrote:2) Shouldn't you use math.abs() first when a Declination is negative? Lua's math.floor() function returns the integer "less than" a value given, so—since this Declination (-23.17) is negative—it runs into problems because math.floor( -23.17 ) should return -24. I always "save" the negative sign as a boolean, then use math.abs( ) before the conversion, then add the sign back to the degrees.

Right! I took the code from the degTohms function and removed math.abs(deg / 15).
Then, I just forgot to add back math.abs(). Thanks! This is fixed now.

Vincent, thank you.
It works perfect now

Tim