Closed for Company Meetings: Between September 18 (5pm PDT) and September 22 (12pm PDT), Support and Sales requests will be delayed. Only time-sensitive issues will be addressed during that time. Thanks for your patience.
Scale formula clarification
Nov 20 2011 | 11:52 pm
There are two posts discussing the formula for the scale object, but none really answer the question posted.
If the formula from the reference is:
y = b e-a log c ex log c
Where:
y = result
x = number to scale
a,b,c = the "three typed in arguments"
e = base of the natural log
My question:
There are 4 mandatory arguments, 5 with exponential scaling (which is why I'm interested in the formula). Given only three (a,b,c) - how does this work?
Also, what are the operators in the formula? I'm guessing:
y = b * (e-a) * log(c) * ln(x) * log(c)
Anyone dug in deep enough into their own scaling object?
- Nov 22 2011 | 2:40 pmI found something similar elsewhere, not the Max object, but it seemed like it did the same thing, no exponential element though. So, if scale has a b c d for low/high input/output, and v is the value to scale, the formula was:c + (d-c)*((v-a)/(b-a))I don't know about the scaling exponent, whether it's applied after all this, or is worked into the formula somehow. And I'm not sure this is even the right formula for [scale], but it works in the patch below:
- Nov 22 2011 | 2:52 pmhere are my scale-objects... the basic expr here is: expr (exp((($f1-$f2)/($f3-$f2)-1)*$f6)-1)/(exp(-$f6)-1)*($f4-$f5)+$f5 which works like scale but has an easy logarithmic scaling, where 0 is linear.
- Nov 22 2011 | 3:25 pmFantastic, thanks Klaus! Too bad your ll.og abstractions don't show up in a forum search - could have saved you the trouble...Those are really great, and likely useful for my students as well.Cheers!
- Nov 22 2011 | 3:53 pmthanks jeff, well ll.og is just one of many objects, that are included in the ppooll distribution. there is more useful stuff in the whole package ;) cheers
