Alignment displaced in cetz content

Questions
,
1

content displacement

content is displaced from the center point of the circle frame of content element in cetz.

#import "@preview/cetz:0.5.2"

  #cetz.canvas(length: 1cm, {
    import cetz.draw: *
    set-style(line:(mark:(end:(symbol:"stealth",fill:black))))
    let (_P1, P0, P1, P2, P3, P4, P5, P6, P7, P8) = (
      (-1, 0),
      (0, 0),
      (1, 0),
      (2, 0),
      (3, 0),
      (4, 0),
      (5, 0),
      (6, 0),
      (7, 0),
      (8, 0),
    )
    line(_P1, P8)
    let P_Collection = (P0, P1, P2, P3, P4, P5, P6)
    // P_Collection.forEach((p)=> line(p, (rel:(0,0.1), to:p)))
        set-style(line:(mark:none))
    for p in P_Collection {
      line(p, (rel:(0,0.1), to:p))
      content(p, [#p.at(0)],anchor:"north", padding:0.5em)
    }
    content(P8, [x/cm], anchor:"north", padding: 0.5em)
    set-style(content:(frame:"circle", padding:0.1pt,fill:gradient.radial(rgb("#eeeeee"),rgb("#449999")), stroke:none))
    content(P0, [+])
    content(P6, [-])
  })

alignment-displaced
alignment-displaced827×331 6.66 KB

As shown in the image above. The plus and minus sign are not placed exactly in the center of the circle frame. How can I fix this problem?

Can those encountered similar problems share your solutions here?

Your sharing answer is very helpful to me and I’m very thankful.

2

Try putting the symbols in block equations, which are optically aligned, instead of content. Like content(P0, $ + $), with spaces around the plus.

Both normal content […] and inline equations $…$ vertically align by the text baseline, which depending on the font might look a bit off, while display equations use proper alignment based on bounds.