How to create a panel on the right side of the layout for drawing a chart y-axis ?

Question

I can't see how to position a new panel4 across panel1, panel2, panel3 on the right side for drawing my y-axis:

plot: [
    pen green line 5x404 5x440 pen gold fill-pen 0.255.0 box 3x424 7x418 line 10x396 10x422 pen gold fill-pen 0.255.0 box 8x418 12x402 line 15x397 15x436 pen gold fill-pen 255.0.0 box 13x401 17x435 line 20x429 20x447 pen gold fill-pen 255.0.0 box 18x434 22x446 line 25x441 25x464 pen gold fill-pen 255.0.0 box 23x446 27x463 line 30x445 30x493 pen gold fill-pen 255.0.0 box 28x461 32x482 line 35x470 35x504 pen gold fill-pen 255.0.0 box 33x481 37x492 line 40x466 40x498 pen gold fill-pen 0.255.0 box 38x491 42x477
]

  grid: [1100 600]
  step-grid: 5
  max-n-points: (grid/1 / step-grid) - 1
  x-axis-border: 20
  Y-margin: 10
  X0: 5
  grid-color: coal


  main: layout/size [
      origin 0x0
      space 1x1
      panel1: box 1100x580 black effect reduce [
      'line-pattern 4 4
      'grid 30x30 0x0 (grid-color)
      'draw plot
      ]
      panel2: box 1100x0 black
      panel3: box 1100x20 black
  ;answer thanks to Graham
  across
  at 1100x0
  panel4: box 40x600 black effect [draw [pen coal line 0x0 0x580]]
  ] 1140x600

  view main

Answer 1

You need to look up the layout word 'across.

And also the layout word 'at.