Re: Multiplot magnitude issue

Posted by chrismlt on Feb 29, 2016; 2:23pm
URL: http://astroimagej.170.s1.nabble.com/Multiplot-magnitude-issue-tp267p365.html

Karen,

Many thanks for your consideration and help. Very useful reply, as usual !

About, the small «? » bug concerning C4 data in mag, I have done some tests, but, at least, I could not reproduce the sequence from which the odd car appears in the Multi-plot Ydata. The only detail I did notice is (before any other action in made in the table), when you click on the blue double arrow next to the page rel check box, this also put a « ? » car in the scale value. This is probably related to the previous issue.

Well, I confirm you that the green « Norm Mag Ref » button in in cause about the very secondary bug in the Multi-plot Ydata table I told you previously. One needs, sometimes to click several time to cause an action with this button, or sometimes there is some delay when updating the plot. That is almost nothing, and not very important, I think. At least, this is not related to the Fit mode/trend/select/dataset buttons.

Well, I also did notice something amazing in the measurements table when using the « Multiplot reference star stettings panel », when using a magnitude related plot.

I've tried to switch between comp stars, so as to see the influence of a particular star on the target magnitude, in order to find any unappropriate/variable star in my comps – something regular I think – ; when doing this by clicking on the « cycle enable star less one » button, or by directly clicking on a « star box », so as to uncheck it, or by using the « cycle individual » button, then the magnitude of the star and that of the target are altered. The comp is definitely altered, no matter if you go back, and never return to it's pre-defined magnitude value.  

Ie : C2 is 13.54 mag on each line Source_AMag_C2 from image 1 to image 100. When cycling between stars, C2 become Source_Amag_T2, with 13.541245, 13.539845, 13.540548 and so on. When cycling further, it becomes Source_AMag_C2 once again, but the values stay as  13.541245, 13.539845, 13.540548. It never return to the original value of 13.54.

So, if you toggle between all comps stars, the target magnitude could be considerably altered, until the target is compared only to the magnitude of the last remaining comp star. Then, nothing is ever  changed, no matter what you do in the panel.

I also noticed, that, even if a comp is considered as a target after cycling, the value of the « new » target is not changed if the comps are modified afterwards.

Ie : when cycling, C2 becomes T2, with a mag changing from 13.54 to, say, 13.559847 etc. If you uncheck now C3, the all comps mag is changed, and T2 mag should be changed too, goind from 13.559847 to 13.560047 maybe. This is not happening, in fact, and C2 stays at 13.559847.

Maybe I've missed something, but this is possibly a source of error.

Anyway, if we know there's an error here, probably the best thing is not to use this process here.

Sorry to bother you with details, the weather is catastrophic here, so I could not observe any star since weeks … So I stick to the computer for software testing;-)

Have a nice week,
Christophe