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Array

Array repeats the selected lines in the sketch editor in rows and columns, or around a centre you click, from counts and spacings you type. The original counts as the first item, and a preview shows every copy before you press Enter.

What it is

Array copies what you selected many times in one go, in two ways. In rows and columns, the copies are laid on a grid with the spacing you type, or touching each other when you type none. Around a centre, they are spread over a full turn, or over the angle you type, each copy turned with its place unless you ask it to keep its bearing. The original is the first item of the array and does not move.

Array works on the lines as you drew them: selecting one side of an outline repeats the whole outline.

When to use it

Laying a regular set of shapes, such as a grid of square inlays or a ring of petals.
Spacing copies evenly where Copy would need one click each.

The steps

Choose what to repeat. In the sketch editor (see Select for the ways in), select the lines with Select first, or arm Array and pick them after.
Arm Array. Type A then R quickly, or click Array on the editor's toolbar. The hint at the cursor says to repeat the selection in rows and columns, or around a centre, typing 3x2x0.5x0.4 or a count and an angle.
Pick the lines, if none are selected. Click lines to add them, Shift and a click to take one back out, drag a box to the right for the lines wholly inside or to the left for every line it touches, or press F for a fence. Press Enter when done.
For rows and columns, type the grid. Type the columns, x, the rows, and press Enter: 3x2. Add the spacing from one item to the next in the project's units: 3x2x0.5 uses 0.5 both ways, 3x2x0.5x0.4 sets the columns and the rows apart. A negative spacing lays the copies the other way. While you type, the copies are previewed and the hint says how many items there will be in all.
Or, around a centre, click it and type the count. Click the centre; it snaps like every point of the editor, and you can also type it as x;y. Then type the count and press Enter to spread the items evenly over a full turn, or the count, x and an angle in degrees to spread them over that angle, the last item landing at the end of it: 6x180. A negative angle turns clockwise. Press R before Enter to keep every copy upright; the hint says items keep their bearing.
Carry on. The copies are added, the originals stay selected, and you can type another array. Escape drops the centre, then goes back to Select.

What it refuses

An empty or oversized array. A count under one, or more than 2,500 items, is refused with that array is empty or too large.
Counts with nothing selected. Until at least one line is picked, typed counts are not taken and Enter asks again to select objects.
Part of a line. Each item is a whole line as drawn.
The shape in force. The dimmed shape behind your drawing cannot be repeated.

What it writes to the contract

Nothing until you press Done. The whole array is one step inside the editor, and Ctrl+Z takes it back in one go. The contract changes when you press Done, or Enter with nothing in progress, as one step you can undo: what the lines enclose becomes the window's or door's profile, points [u, v] in metres across the wall and up from the floor, or the pattern area's outline in the room's floorAreas or ceilingAreas, points [x, y] in plan metres.

Done takes exactly one outline, so items that stand apart are refused as several outlines. An array helps only where its items cross or touch so as to close one outline, such as the lobes of a rosette drawn over one another.

Common questions

How do I lay three columns and two rows 50 by 40 centimetres apart?

Select the lines, press A then R, type 3x2x0.5x0.4 and press Enter. The counts include the original, so this adds five copies.

What spacing is used if I type only the counts?

The width and height of what you selected, so the copies just touch each other.

How do I spread copies around a centre?

After picking the lines, click the centre, type the count and press Enter for a full circle, or the count, x and an angle in degrees for part of a turn. Press R before Enter to keep every copy upright instead of turning it.