unfold {unfoldr} | R Documentation |
Unfolding the (joint) distribution of planar parameters
unfold(sp, nclass, maxIt = 64, nCores = getOption("par.unfoldr", 1), ...)
sp |
section profiles |
nclass |
number of classes |
maxIt |
maximum number of EM iterations |
nCores |
number of cpu cores used |
... |
optional arguments passed to |
This is a S3 method for either trivariate stereological unfolding or
estimation of 3d diameter distribution of spheres (Wicksell's corpuscle problem). The function
aggregates all intermediate calculation steps required for the unfolding procedure given the data
in the prescribed format and returning the parameters as count data in histogram form.
The section profiles object sp
, see sectionProfiles
, is either of class
prolate
or oblate
for the reconstruction of spheroids or in case of spheres
the sp
is simply a numeric vector of circle diameters. Here, the class of section profiles
corresponds to the type of objects that will be reconstructed. The number of bin classes is set
by the argument nclass
which is either a scalar value in case of Wicksell's corpuscle problem
or a vector of length three defined in the order of the number of size, angle and shape class limits.
Using multiple cpu cores during the calculations is controlled by either setting the option 'par.unfoldr'
to a user chosen amount of cores or by the argument nCores
directly.
The return value of the function is an object of class unfold
whose arguments are as follows
N_A (trivariate) histogram of section profile parameters
N_V (trivariate) histogram of reconstructed parameters
P array of coefficients
breaks list of class limits for binning the parameter values
object of class unfold