How to make a square axis plot in Calc?

I would like to produce a linear regression scatter plot to compare two series of data that, ideally, would be equivalent (such as experimental value versus theory). To avoid distorting the axis, I wish for both axis to have the same dimensions - a square is a square. However, even when I make the width and height of both the chart and chart area equal dimensions, 10 units on one axis is not quite the same number of pixels as 10 units on the perpendicular axis.

Can a perfectly square axis plot be achieved in Calc?

Edit your chart. Click on the chart wall (inner frame). Right click and select “Position and Size”. Under “Size” you can set width and height to the same number what gives you a square.

As noted in my question (using a different wording), I have set the inner and outer frames to equal dimensions, but the resulting axis are not quite perfectly square. They differ by about 13 pixels which makes the axis appear ‘off’. Perhaps this is a bug?