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Re: Unloading at a given state


nejib hadda a écrit :
Hi Bruno,
 I've been looking into random distributions available on YADE, and I
think that the  boost::uniform_real<> is OK for my work, actually it is
not the fact of having an uniform distribution that is worrying me,
rather it is how to fix a range of radii [rmin, rmax] (Do you agree that
my distribution is still uniform even if rmax is 10 time (in my study
case) greater than rmin: it is the percentage of each r  (rmin<r<rmax)
that makes my distribution uniform or not. is it that what it is meant
by "uniform" on YADE or not?).

Uniform means all radii in the range [rMean-rRelFuzz; rMean+rRelFuzz] are generated with equal probability. In TT interface, rRelFuzz is named stdDev (what does "Fuzz" mean btw?). Be carefull, it is not uniform in terms of mass distribution, and some specialists of granulometries would not call this uniform.

Also I've met a problem that I could not explain when changing values
into boost::uniform_real<0,1>, depending on the values entered YADE
returns spheres coming out of the box or can't generate the requested
number of spheres. Tell me if I should not change these values or if I
need to do something else when changing them.

Currently, positions are generated using the same uniform PDF (Prob. Density Function) as sizes. If random numbers are between 0 and 2 instead of 0-1, positions will be between 0 and 2*sizeOfTheBox. You need to uncouple size PDF and positions PDF (the second should always be uniform I think). Read the current makeCloud carefully, or perhaps try writing your own algorithm. It might help you to understand what is going on there.