decimal places for distances

[joshinils]

I want to enter very specific lengths, not just in the scale of several meters, but centimeters.
for example the distance between individual bollards, or specific lengths of parking spaces, etc.
these are between 1 and 2 metres, for example 1,4 or 1,7m
or i have counted an amount of stones and measured the stones widths, to calculate lengths at home.

this plugin is the next best thing compared to entering the length itself of a segment, which seems to be impossible?
so working with constraints etc. is not possible in josm at the moment

[kolesar-andras]

Do you need display smaller units or also contraint (snap?) to given lengths?

[joshinils]

Ideally both.
Realistically a precision smaller than a few centimeters is not possible to either measure correctly or put in the correct position (relative to other objects, coordinates, or imagery) anyway, so snapping to a multiple of at minimum 1cm is best. A setting for how small this minimum is would be great.

I wish it'd be possible to have a workflow with more constraints, where I can manually enter a specific length for a segment between two nodes.
Then afterward have it calculate the best possible shape for the given constraints. But that would probably lead to planar graph constraints and least squares solutions etc. I think.