Xsample {LIM} | R Documentation |
Given an inverse input list, randomly samples the unknowns, using a Bayesian MCMC method
Xsample(lim,exact=NULL,...)
lim |
a list that contains the linear inverse model or linear programming specification, as generated by function Setup |
exact |
if not null, a vector containing the numbers of the equations to be solved exactly; if NULL, all equations are considered exact |
... |
extra parameters passed to function xsample from packagelimSolve |
For overdetermined LIM problems, the inverse equations may be split up
in equations which have to be exactly met and other equations which have to be approximated.
exact
is a vector with the exact equations
The default settings of xsample
will often not do.
For instance, the default consists of 3000 iterations (iter
) and a jump length of
jmp
of 0.1. You may need to increase one of those to ensure that the
entire solution space has been adequately sampled.
a 2-columned vector containing the minimum (column 1) and maximum (column 2) of each unknown
Karline Soetaert <k.soetaert@nioo.knaw.nl>
Varranges
which estimates the ranges of inverse variables
Plotranges
to plot the ranges
function xsample
from packagelimSolve
# sample solution space xs <- Xsample(LIMRigaAutumn,iter=500,jmp=5) # remove flows that are invariable (sd=0) xs <- xs[,-which(sd(xs)==0)] #pairs plot pairs(xs,gap=0,pch=".",upper.panel=NULL)