So, my sister wants new blinds hung in her bedroom. Going by the Big Orange Box instructions, I measure top and bottom width (to check parallelism), diagonals (to check squareness), and height in the middle.
The openings are neither parallel nor square, although they’re not out by much; I’ve seen much worse.
I set about trying to find the widest blind that will fit in each opening. I can’t find an on-line calculator, and when I try to figure out an algorithm myself (while trying to chip the rust off my Python skills), it turns out to be surprisingly difficult. Any given case is straightforward, using Pythagoras, but there seems to be no general solution. And that’s assuming that the top and bottom are parallel and level.
I mention this at the dinner table.
“Why not just measure the old blinds?”
Good question, Mom. Good question.
I’m still piddling about with writing a calculator, just as an exercise. And I’d like to find an online calculator.
Note: the math might be a bit easier if you measure width of the opening top and bottom, length of both sides, true plumb height at both sides, and both diagonals. But I think you can do it with the usual top and bottom width, overall height (assume level), and the diags, and given that those are the measurements most window blinds sites ask for, that would be best.
Inputs and results to the nearest eighth of an inch, please. If you round, round down — a blind that is too large by the height of the drywall texturing, a sixteenth of an inch or less, will not work. Piss off with your sissy millimeters.
A command line calculator is fine by me, but it must work under Windows as well as Unix.
