How can I use attach in such a way that the layout is not affected?

Questions
1

I am trying to lay out some school-level mathematics and I’d like to show the borrowing/relabelling involved in a subtraction. The closest I can get is shown below, but you can see that when I add the workings (in red), this moves the digits ‘5’ and ‘2’ so they are no longer aligned.

image
image611×719 51.5 KB

The second part of the diagram was generated using the code below.

$#grid(columns:5,
align: center,
stroke: (x, y) => if y == 2  and x >= 0 { (top: 0.4pt + black) },
inset: (x, y) => if x == 2 { (x: 0pt, y: 3pt) } else { (x: 2pt, y: 3pt) },
[], [$attach(tl: #text(red)[4], cancel(stroke: #(paint: red), 5))$], [.], [$attach(2, tl: #text(red)[1])$], [7],
[$minus$], [3], [.], [4], [2], 
[], [1], [.], [8], [5])$

I couldn’t work out how to use place (or something else) to make it so the attachments did not affect the layout of the original text shown in black.

2

Would aligning your columns right help you?

image

1 Like
3

Thanks for this suggestion, which I had not considered. One issue is that the decimal points are not centred nicely (but I can change it to center that column), but a bigger issue is the fact that columns with attachments are much wider.

I would like it to have the exact same width as the original grid, but just with the items attached, but as you can see, it is now much wider.
image

4

I think, you should use place in that case for absolute positioning. dx and dy should get your supscript in the right place!

5

I couldn’t work out how to get place to work with the attach function though. I also couldn’t really work out how to manufacture the right appearance of small text using place directly.

6

The following seems to work:

#let annotate(it, with: none) = math.attach(it, tl: box(
  place(
    bottom+right,
    text(red, with),
)))

#let strike = math.cancel.with(stroke: red)

#grid(
  columns:5,
  align: center,
  stroke: (x, y) => if y == 2  and x >= 0 { (top: 0.4pt + black) },
  inset: (x, y) => if x == 2 { (x: 0pt, y: 3pt) } else { (x: 2pt, y: 3pt) },
  [], $annotate(strike(5), with: 4)$, $.$, $annotate(2, with: 1)$, $7$,
  $-$, $3$, $.$, $4$, $2$, 
  $$, $1$, $.$, $8$, $5$,
)

image

I put the place call in a box: the placed content doesn’t take any space so the box will be zero-size, at the correct position. Aligning the bottom-right of the placed content with the (bottom-right of) the zero-sized box works well. (I’m not sure what happens here with spacing when you don’t include the box.)

1 Like
7

The use of the box was the missing piece of the puzzle for me! Thank you.