Hi all,

How do you fit a sieve analysis data to a statistical function?
I have many sieve analysis data of crushed rocks and I'd like to find out
which statistical distributions describe the particular particle size
distributions (PSD) the best. So basically I need to find fitted parameters
to statistical distributions (mostly weibull and truncated lognormal).
Here is an example of particle size (in microns) versus percent weight
retained.
Sieve size   Wt%  Cumulative passing%
+250           0.1         99.9
-250+180    2.9         97
-180+125    9.5          87.5
-125+90      21.2        66.3
-90+63        29.4        36.9
-63+45         26          10.9
-45               10.9

PSD<-data.frame(size=c(250,180,125,90,63,45,0),retained=c(0.1,2.9,9.5,21.2,29.4,26,10.9),cumulative=c(99.9,97,87.5,66.3,36.9,10.9,0))

The above example is truncated to 350micron and I can't have particles
with minus dimension. Any help will be greatly appreciated.

Thank you,

Zorig

	[[alternative HTML version deleted]]

