[Bug] g.gui.tplot: y values in stvds plots are unordered

[veroandreo]

Describe the bug
I'm trying to plot the time series values of a points STVDS with g.gui.tplot. The STVDS is created with t.vect.observe.strds. When plotting the values of any single point I get something like:

Values of Y axis are not in order and they depict a 1:1 line.

To Reproduce
Steps to reproduce the behavior:

1. Download the modis_lst mapset and unzip it within NC location
2. t.vect.observe.strds input=schools strds=LST_Day_monthly output=LST_schools vector_output=LST_schools columns=LST
3. g.gui.tplot stvds=LST_schools cats=1 attr=LST
4. See plot

Expected behavior
Y axis values should be ordered correctly so the plot would show the actual fluctuation.

System description:

GRASS version: 8.4.0dev                                                         
Code revision: dec42666ca                                                       
Build date: 2024-04-13                                                          
Build platform: x86_64-pc-linux-gnu                                             
GDAL: 3.7.1                                                                     
PROJ: 9.2.1                                                                     
GEOS: 3.12.0                                                                    
SQLite: 3.42.0                                                                  
Python: 3.11.6                                                                  
wxPython: 4.2.1                                                                 
Platform: Linux-6.5.0-28-generic-x86_64-with-glibc2.38

@lucadelu any hints?

[lucadelu]

No, I don't have any idea.

I these days I have no time to check it, I hope in the next weeks.

[echoix]

Without knowing anything about the implementation, I can think of two other reasons that could do that, to check if it's what happening:

• The y axis labels on the graph come from a categorical variable, so they don't have a position. So they aren't a number, they would be a string
• The labels are trunctatad, and you only see the end of the string

[veroandreo]

Without knowing anything about the implementation, I can think of two other reasons that could do that, to check if it's what happening:

• The y axis labels on the graph come from a categorical variable, so they don't have a position. So they aren't a number, they would be a string

This is what I suppose too. The y value seems to be obtained here: https://github.com/OSGeo/grass/blob/f8115df1219e784a7136e7609f4c9bb16d928e2f/gui/wxpython/tplot/frame.py#L693C25-L695C29 but I'm not sure how to test it

[echoix]

Since I suspect something wrong with type handling, I would place a breakpoint and step through it, but I won't be on a computer for the week. I would look if the int(cat) is correct, and if the data structure represents correctly what we wanted (ie: it gets the elements we want), and what branch conditions are taken. (Make sure that it is the good lines we are investigating).