# Circle with Offset radius is not round

I want to draw some circles with different radius, and I want to keep them to be circle in any AspectRatio setting. I found that Offset needs to be used in radius to make absolute. However, I found peculiar behavior.

Graphics@{RGBColor[1, 0, 0], Thickness[0.3], Circle[{0.4666666666666667, 0.48315}, Offset[{0.1474,0.1474}]]}


Shows

What is wrong? It should be a circle. How to make it normal circle?

• The syntax of Offset is wrong. It is in place of the radius and it is not of the form Offset[{..,..},{..,..}]. And you choose an incredible large value in Thickness, put it to e..g. 0.01. Dec 2, 2020 at 10:21
• @DanielHuber You are right. Though not documented, but it seems that Offset[a] is equivalent to Offset[{a,a}]. Anyway, it doesn't solve the problem. The graphics is vector image, I don't see why a circle should not appear to be a circle at any scale Dec 2, 2020 at 11:30
• I do not understand your definition of the radius. What should a radius of "Offset[..]" mean? Dec 2, 2020 at 11:40
• @DanielHuber According to the doc of Offset: "Offset[{dx,dy}] can be used to specify an absolute radius in a Circle or Disk object. " Dec 2, 2020 at 12:36
• I get a circle (V12.1.1, Mac): i.stack.imgur.com/WMPIS.png Dec 2, 2020 at 14:10

This is not the output I get, but I am not surprised that the output is corrupted:

• You are requesting a circle with a radius of 0.14 pixels
• You set the thickness of the line to be 30% of the image width

Here's a more reasonable version:

Graphics@{RGBColor[1, 0, 0], Thickness[0.01],
Circle[{0.4666666666666667, 0.48315}, Offset[{20, 20}]]}


This is still very strange, as the circle radius is fixed, while the thickness is relative to the image width. Try resizing the image. This is more reasonable:

Graphics@{RGBColor[1, 0, 0], AbsoluteThickness[3],
Circle[{0.4666666666666667, 0.48315}, Offset[{20, 20}]]}