Zoom rectangle for rectangular diagrams

[georgtree]

Hello!
I would like to see the rectangle selection tool for graphs, because now for transient simulation you have to go to properties of particular graph and set x and y limits manually, it it possible to add this feature in future?

[medwatt]

Also, a vertical/horizontal cursor will be great.

[iwbnwif]

This feature would also be useful for tuning so you can home into a specific point on the Smith chart. It would be best if the marker font remained the same and didn't zoom with the chart.

[iwbnwif]

I've had a quick go at implementing this by setting the existing limits via a mouse action. So far, only rectangular diagrams are supported and other plots are undefined. I would like to a bit of refactoring to simplify the implementation of this, in particular to use QTransform to map between various coordinate systems.

This is what it looks like:
Screencast from 21-01-24 20:25:05.webm

Initial code is here: https://github.com/iwbnwif/qucs_s/tree/graph_limits_by_mouse

[zergud]

looks amazing!
exactly as needed for the RectangularDiagram
create PR when you're ready

p.s. zoom for other type of diagram in next step

[iwbnwif]

Thank you. There are two main problems at the moment that I would like to fix before submitting a PR:

1. Dragging the mouse to zoom over a diagram with lots of data points is slow. I suspect that the chart is being redrawn on mouse moves, so I will need to look into this.
2. The step sizes are arbitrary (basically a simple subdivision of the new limits) which results in some wild values on the axis.

As mentioned above, I would like to discuss about refactoring some of the diagram code to make transforms between coordinate systems simpler. This will pave the way for cursors and mouse dragging of markers. Anyway, we can discuss that on a separate issue when the time comes.

Unfortunately, I am still a real noob when it comes to git. I hope that the commits are clean, but I have had a bit of trouble merging some recent commits in master to my 'graph_limits_by_mouse' branch :(

[ra3xdh]

The proposed feature implemented by #485. Closing as completed. It still be unclear how to zoom Smith and Polar charts by mouse selection.

[zergud]

need to implement separate zoom for two Y-axes

[iwbnwif]

need to implement separate zoom for two Y-axes

I am not sure how to do this. I suppose we could use a keyboard key (e.g., Ctrl or Alt) for the selection, but which X-axes value will take priority?

[zergud]

Why?
Can we rrpeat the same things for for second y-axis?
Min max step differs

[iwbnwif]

Do you mean scale both axes by the same amount? If so, yes that should be simple to implement.

[zergud]

I will offer my solution in PR, if you don’t mind

[iwbnwif]

I will offer my solution in PR, if you don’t mind

Of course not!

[zergud]

please check branch 305-zoom-both-axes

1. fix right button
2. independed scale for Yleft YRight
3. recalculate step

[iwbnwif]

Thank you, that looks great!