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### equation

Jun 22 2011 | 11:13 am

hi

i try to make the equation on the pict.

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)

if anyone can help me !
thanks
f

[attachment=164828,2384]

###### Attachments:
1. area.tiff

Jun 22 2011 | 11:17 am

This seems to a perfect task for [expr].

Jun 22 2011 | 11:57 am

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 ?

thanks
f

Jun 22 2011 | 12:05 pm

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

— Pasted Max Patch, click to expand. —

thanks
f

Jun 22 2011 | 12:12 pm

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].

Jun 22 2011 | 12:21 pm

ok

thanks
f

Jun 22 2011 | 12:59 pm

split it up.

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

Jun 22 2011 | 10:33 pm

Throw some iteration in there and do the maths:

``````
-- Pasted Max  Patch, click to expand. --

```
```
Jun 23 2011 | 11:03 am

hi

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

all the best
f

Jun 23 2011 | 10:09 pm

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

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Forums > MaxMSP