# Decimal precision

I would like to set the staff line thickness to 0.5pt. OK, so that’s 0.5 ÷ 6, 0.08333 spaces. I enter that, and Dorico puts “2/25” in the box, which is of course 0.08.

Dorico’s default of 1/8th spaces gives a mouse-over tool-tip of “0.13” (which is the value in the Bravura json file). No such mouse-over appears for the custom value.

OK, 0.005 of a space (0.03pt) may be a trivial amount, but these kinds of roundings can cause errors when values need to be multiplied across a page. As a proportion of the height of an A4 page, it’s just over ⅓ of an inch! (0.03 pt x 842 pt).

1. Can we have decimal values?
2. Can we enter values in a variety of units?

Many people familiar with DTP apps will be used to working with line thicknesses in points, and values of 0.5, 0.625 and 0.75 are commonplace. The 'default" step in Dorico is: 0.75 pt, 1.5pt, 3pt – which is quite big.

I agree that the alternative, seen elsewhere, of having document settings with values like “0.049236” is equally unhelpful. So, yes, I’m looking for the middle bowl of porridge.

I agree with this whole post. I was collating information to post exactly this.
I’ve had a longstanding ‘house style’ for material that will be read at sight and I can only approximate this in Dorico at the moment. The differences are not big, but they have been balanced carefully, over a long time.

You can enter fractions directly. If you want 1/12 of a space, just type 1/12 in the box.

I just tried this:

• start a new project
• change the spacing to 1/12
• save the project
• quit Dorico
• restart Dorico
• open the project

The Engraving Rules still showed the spacing as 1/12 even though the mouse-over showed 0.08. so I would guess the program is actually using “exactly” 1/12.

One way to verify that would be export the score as SVG graphics and see what data in the SVG file actually says. I didn’t fully “decode” the SVG, but the numbers seem to be given to 6 figure accuracy, and it starts by defining 10 lines, 4.96 apart, with width 0.413333 which look like the grand staff.

In the Dorico setup, the (default) staff size was 4.96pt, and 4.96 / 0.413333 = 12.00001, so it looks to me as if the lie width is “exactly” 1/12 space, not rounded to 0.08 space which would be 12.5 not 12.00001.

Dorico certainly “knows” how to do arithmetic with fractions in other situations, e.g. splitting complicated nested tuplets across barlines!

Dorico does indeed use rational values top to bottom internally, but allows you to type decimal values into those spin boxes if you want to, which it then converts into rational values. Because of course there is inherently a loss of precision in converting from decimals to fractional values, if you’re able to think in fractions that’s generally the way to go.

That said, we do want to make it easier to supply values in any of the supported units of measurement, and we do plan to do this in the future.