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IDProjectCategoryView StatusLast Update
0002179SkyChart1-Softwarepublic19-10-03 10:48
ReporterMattia VergaAssigned ToPatrick Chevalley 
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionfixed 
PlatformPCOSLinuxOS Version64bit
Product Version4.1 SVN 
Target Version4.2Fixed in Version 
Summary0002179: Problems with Catgen generated catalogs
DescriptionI'm starting to build a catalog of nebulae outlines using Catgen. See the attached project and sample data files.
I've noticed a few problems while creating the catalog with Catgen:
- if I choose to create a text catalog instead of a binary catalog, the result is an empty catalog
- after creating a binary catalog and adding it to the catalogs list in Skychart, if I modify the catalog I cannot see the edits unless I quit and restart Skychart. Even deleting and readding the catalog to the catalogs list doesn't refresh the contents, it seems Skychart always maintain it in cache and doesn't refresh it.
- what does the "maximum magnitude" parameter mean for nebulae outlines? I need to set it to 6 because if I left it to 0 nothing is displayed in the chart
TagsNo tags attached.

Activities

Mattia Verga

19-09-03 09:51

reporter  

outlines.zip (2,749 bytes)

Patrick Chevalley

19-09-04 17:16

administrator   ~0005899

I Mattia,
Very nice project!

There is a very long time I not do a line catalog myself so I must try to remember some points.
What is sure is the text catalog was added after I make the default line catalog, so text line catalog is probably untested.

I look at the code and find the mapping between the text operation (start,vertex,end) and the numeric operation number is not implemented. This work when making the binary file because catgen do the replacement. But doing the replacement a run time from the text file is probably not good for the performance.
So it is probably best if you replace this text by the number directly in the file:
sed 's/start/0/; s/vertex/2/; s/end/1/' simplified.dat
Then change the "line operation" field length to 1 in catgen and it work.
I tested to modify a point in the file and it is immediately show on the next redraw of the chart. So this is the best mode to test a work in progress.

Yes, single file binary catalog are only read from file the first time, then they are keep in cache for all the session.
If this is really required I can add some checking of the cache validity using the file date for example. But this way to work is good for performance when the catalog is complete and no more change are done. Maybe it is best you use the text file catalog for the development and make the binary format only for release.

The "maximum magnitude" is not used, probably any positive value as the same effect. If it not work with 0, this is probably a glitch in the catalog selection procedure.
Also the Epoch field is of no use for any data without proper motion, but I let it for all the object type and this not hurt.

You can probably advance with the change to use the numeric line operation for the text catalog.
Let me know if there is something I can do to simplify your task.

Mattia Verga

19-09-04 18:34

reporter   ~0005900

Thanks Patrick, using {0,1,2} instead of {start,end,vertex} made the trick.
Another thing not mentioned in the manual about text catalogs is that the data source MUST be in the same directory of the catalog header: I used to have the data source in a subdirectory and it didn't work, when I copied the data source in the same dir it started working.

About binary catalogs, it's fine they're kept in cache, but I would have expected that if I completely remove a catalog (by the "delete" button which removes the line) from the catalog list, it should refresh its contents if I reload it without quitting the program.
I think this means that even if I remove a catalog from the list, Skychart always keeps the data in cache forever (?)

Patrick Chevalley

19-09-04 19:10

administrator   ~0005901

Yes, the text data and the files .hdr and .info2 must be in the same directory to allow to install the catalog anywhere on any computer. If I record the full path, the catalog work only on the specific directory on the computer you build it.

You are right I must delete the cache when a catalog is removed.
This is done by:
https://github.com/pchev/skychart/commit/39bb31c9c110283e199830e4af7ed9b498ae9dc5

With this change you can test a new version of a binary catalog by delete and add again.

Mattia Verga

19-09-07 17:38

reporter   ~0005903

While testing the differences between line and spline types I've noticed that spline outlines are sometimes rendered quite odd. I don't know much about spline interpolation, but I would expect a single, smooth curve between two consecutive points, not two curves like the example image attached. Is the actual behavior correct?

outlines.png (63,977 bytes)
outlines.png (63,977 bytes)

Patrick Chevalley

19-09-08 09:22

administrator   ~0005909

Yes, there is really something wrong here.

I cannot find such an extreme case in my current set of lines. Can you please send me the data for this object.

Mattia Verga

19-09-08 11:38

reporter   ~0005911

Here it is the source data file. The object in the above image is IC405, but also other objects outlines show some glitches.

outlines_catgen.dat.zip (4,891 bytes)

Patrick Chevalley

19-09-10 16:12

administrator   ~0005924

Thank you for the example data.

This is fixed by :
https://github.com/pchev/skychart/commit/f0d01834d6b5287fc12000498436804dbe46c957

Mattia Verga

19-09-30 19:12

reporter   ~0005982

Thank you Patrick, I confirm this is fixed, splines are drawn correctly now.

Patrick Chevalley

19-10-03 10:48

administrator   ~0005983

Nice, let me know of the advancement of your project.

Issue History

Date Modified Username Field Change
19-09-03 09:51 Mattia Verga New Issue
19-09-03 09:51 Mattia Verga File Added: outlines.zip
19-09-04 17:16 Patrick Chevalley Assigned To => Patrick Chevalley
19-09-04 17:16 Patrick Chevalley Status new => assigned
19-09-04 17:16 Patrick Chevalley Target Version => 4.2
19-09-04 17:16 Patrick Chevalley Note Added: 0005899
19-09-04 18:34 Mattia Verga Note Added: 0005900
19-09-04 19:10 Patrick Chevalley Note Added: 0005901
19-09-07 17:38 Mattia Verga File Added: outlines.png
19-09-07 17:38 Mattia Verga Note Added: 0005903
19-09-08 09:22 Patrick Chevalley Note Added: 0005909
19-09-08 11:38 Mattia Verga File Added: outlines_catgen.dat.zip
19-09-08 11:38 Mattia Verga Note Added: 0005911
19-09-10 16:12 Patrick Chevalley Note Added: 0005924
19-09-30 19:12 Mattia Verga Note Added: 0005982
19-10-03 10:48 Patrick Chevalley Status assigned => resolved
19-10-03 10:48 Patrick Chevalley Resolution open => fixed
19-10-03 10:48 Patrick Chevalley Note Added: 0005983