size in graph coordinates

[markhamnr]

I noticed that functions like JKQTPXYParametrizedScatterGraph::setSizeColumn set the size of a symbol in points, rather than in the plot's own coordinates. Is there a way to specify the size in terms of the axis coordinates I haven't found?

Maybe this is uncommon, but to me, this would be more useful than specifying the size in "points", which is rather arbitrary in the context of a graph. For example, I might wish to plot some kind of probabilities, so that P(x, y) ∊ [0, 1] is the diameter of a square centered at x,y.

[jkriege2]

Hi!
I think when I designed that class ... i thought about which dimension would be best for size (and width) ... first I was thinking along plot coordinates,but then I decided against, because I couldn't find (m)any applications ... but that said, I think it's rather simple to add a mode where you can specify size in plot coordinates as an options (ultimately you only have to change the size-calculation ...).
But also note that this might require scaling differently in x- and y-axis! So circles could become ellipses ...

Best,
JAN

[markhamnr]

That's a good point re: scaling…I really only envisioned using this when the aspect ratio and axis aspect ratio were both 1, or at least the same as each other.

gnuplot allows something similar with the x- and y-sizes controllable independently, so I guess you could make it fully customizable if you really wanted to. But personally, I'm not sure anyone would have a use for this, so I would just pick one axis, use that for the sizing and expect the programmer to manage the aspect ratios accordingly — that is, if you even care to do this at all. :)

[jkriege2]

Not Sure Yet .. but I can propose two things for now:

1. Use JKQTPGeoEllipse (https://jkriege2.github.io/JKQtPlotter/class_j_k_q_t_p_geo_ellipse.html) or obe of its cousins ... but you will have to assemble the plot yourself and can't use the datastore as datasource
2. If you propose a PR, adding what you rnvision: I don't see any reason not to merge that ...

Best,
Jan