Image scale change improvements

[bwdev01]

Changes to pixel size, focal length, or binning currently trigger clearing of calibration. This is unnecessary for minor changes in focal length or pixel size. Also, the current floating point equality check always fails for reported pixel sizes on SX cameras because of approximation.

[bwdev01]

Good point. This was originally a private static function in camera.cpp but I later promoted it to advanced_dialog.cpp and neglected to think about the other use-cases. I just used your suggested change so I went ahead and merged the PR without asking for another review. Thanks. From: Andy Galasso ***@***.***> Sent: Friday, November 29, 2024 7:40 PM To: OpenPHDGuiding/phd2 ***@***.***> Cc: bwdev01 ***@***.***>; Author ***@***.***> Subject: Re: [OpenPHDGuiding/phd2] Image scale change improvements (PR #1260) @agalasso commented on this pull request.

_____ In src/advanced_dialog.cpp <#1260 (comment)> :

@@ -592,6 +592,21 @@ double AdvancedDialog::DetermineGuideSpeed()

} return sidRate; } + +// Floating point equality comparisons can be a problem due to rounding and trivial inequalities. +// PercentChange can be used to see if a change is worth reacting to +double AdvancedDialog::PercentChange(double oldVal, double newVal) +{ + double chg; + if (oldVal > 0) + { + chg = fabs(1.0 - newVal / oldVal); + } + else + chg = fabs(newVal); hmm, the negative case (oldVal < 0) seems odd -- probably won't happen in this pr but could be an unexpected result if somebody else wants to use this method. how about something like this: if (fabs(oldVal) < 0.0001) return 100. * newVal; // not meaningful, but avoids divide by zero return 100. * fabs(1. - newVal / oldVal); — Reply to this email directly, view it on GitHub <#1260 (review)> , or unsubscribe <https://github.com/notifications/unsubscribe-auth/ADDHSV2EZO6OCD3SBDEVGYT2DEXP7AVCNFSM6AAAAABSR47S2WVHI2DSMVQWIX3LMV43YUDVNRWFEZLROVSXG5CSMV3GSZLXHMZDINZQG4YDENBVHE> . You are receiving this because you authored the thread. <https://github.com/notifications/beacon/ADDHSV7BQI3U7RFRBUI2IQD2DEXP7A5CNFSM6AAAAABSR47S2WWGG33NNVSW45C7OR4XAZNRKB2WY3CSMVYXKZLTORJGK5TJMV32UY3PNVWWK3TUL5UWJTUTIPWXW.gif> Message ID: ***@***.*** ***@***.***> >