Names of stars in the constellation Canes Venatici are missing from 1.7

[selden]

Stars in the constellation of Canes Venatici are not recognized by Celestia v1.7 commit c2320637 and others.
They are recognized by Celestia v1.6.1 and v1.6.2.2.

Please restore their definitions.

This .CELX script demonstrates the problem:

Code: Select all

-- this script attempts to mark stars of the constellation Canes Venatici.
-- If they're missing, these markers will appear at the position of Sol, instead.

  celestia:find("Alpha Canum Venaticorum"):mark("orange","diamond",15.0, 1, "Cor Caroli")
  celestia:find("Beta Canum Venaticorum"):mark("orange","diamond",15.0, 1, "Chara")


[ajtribick]

Looks like a side-effect of updating the code for parsing user input to Bayer designations to support component identifiers. In 1.6.x, "Alpha Centauri B" will fail to match "ALF Cen B" but in 1.7.0 it works. Unfortunately the way this was achieved is by treating the final space as the separator between the constellation and the component, so "Beta Canum Venaticorum" gets parsed assuming that "Venaticorum" is the component identifier with "Canum" as the constellation. Since there is no constellation which has the genitive form "Canum" this then fails to match. Similar behaviour will be observed with "Ursae Majoris", "Leonis Minoris", etc.

A reliable approach that works in both 1.6.x with multi-star systems and in 1.7.0 is to use the abbreviated forms for Bayer designations, e.g. "BET CVn".

[selden]

Unfortunately, if that's the problem, the new parser breaks many existing scripts. I really don't have the time to try to find them all.

I believe that Celestia 1.7 needs to recognize all of the Bayer star designations whether they're abbreviated or spelled out and all of the IAU constellation names whether they're abbreviated or spelled out and whether they're in nominative or genitive case. If the new parser can't do that, then it needs to be either fixed or replaced.

[ajtribick]

I doubt this change was done deliberately to break your scripts. Sure, it needs to be fixed for English at some point. What should such a script do if the user's language is set to Spanish, where the first letter of the Greek alphabet is spelled "Alfa"?

[selden]

Unfortunately, to be balanced, I think all of the spellings for the Greek letters should be recognized, no matter what the computer's Locale has been set to. Of course, this depends on people submitting appropriate translation tables.

[ajtribick]

You are welcome to write the code for that. Remember that some languages put the constellation name before the Greek letter!