florent colautti

corresponding to Multiply the x coordinate of each vertex by the y coordinate of the next vertex.

like this : ($1 * $4) + ($3 * $6) + ($5 * $8) + ($7 * $10) + ($9 * $12)

equation

This seems to a perfect task for [expr].


yes sure.... but if i write it on the form : ($i1 * $i4) + ($i3 * $i6) + ($i5 * $i8) + ($i7 * $i10) + ($i9 * $i12) expr don't work, be in black and max window say $ symbol variable out of range...

i don't know what kind of operators used or is it necessary to used several expr ?

yes sure.... but if i write it on the form : ($i1 * $i4) + ($i3 * $i6) + ($i5 * $i8) + ($i7 * $i10) + ($i9 * $i12) expr don't work, be in black and max window say $ symbol variable out of range...
i don't know what kind of operators used or is it necessary to used several expr ?

like this is ok but maybe tyey are a most effective way ?

cant' see your patch here. but the error message is because [expr] takes only up to nine arguments. so you could split the tasks into two expressions or maybe do it in Javascript using a single [js].

if it is a list, use something like zl iter 2 or zl iter 4, then write an an expr.

Throw some iteration in there and do the maths:

thanks Luke, this run good and seems me the most efficiently, and can run with different size of list...

Not a problem, scalability is always good. This way you can change the list length and the offset, happy to help!