Aw: Re: LabPlot+Cantor for GSOC 2014?

Alexander Semke Alexander.Semke at
Wed Feb 12 21:20:38 UTC 2014

> Good to hear, how should I proceed? I have built LabPlot and now going
> through its code. What to do next?
Well, it heavily depends on your understanding of the available code and of 
your programming skills. I think, it's better to start with a sub-project 
where you don't need to know much about the available code. I have an idea for 
such a project.

Please have a look at the following projects:

Both projects seem to be dead or not developed anymore. Digitizer is Qt based, 
so I think one can learn a lot from this project. Several years ago I had to 
exract numbers from a plot in a scientific publication and I used g3data for 
this. This program was far from being user-friendly and modern looking but it 
did the job. Having such a tool in LabPlot would be very nice.  I think of the 
following workflow:
1. you have a plot from a paper where you want to extract the data points from
2. you open the exported image in LabPlot in the to be created tool for 
performing such an extraction
3. you define the coordinate system on the image, define the spreadsheet and 
columns where the data has to be exported (for this you'll need to learn the 
public interface of Spreadsheet and Column classes) and start clicking on the 
4. read data points are either immediately transfered to the provided 
destination or collected temporarily within this new tool and are then 
transfered in a single step.
5. if you have already created a worksheet+plot+curve and selected those 
columns as the data source in the curve, your plot gets immediately updated 
after every click on the data point you want to extract. So in short, you 
click on the image and get the points in your plot.

Plot updates on columns changes and so on - this is already implemented. The 
"only" thing that needs to be done is to create (x,y)-pairs from mouse clicks 
on the image and to put them to columns.

Please tell me whether you want to take this taks now or not. If not, I would 
formulate this as a proposal for the summer.

Another thing that comes to my mind is the nice animation effect for zooming 
in kmplot. Having this in LabPlot would also be very cool :-)


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