set.SB {BBEST} | R Documentation |
Set the coherent baseline
Description
set.SB
sets the baseline, describing coherent neutron scattering caused by uncorrelated atomic motion or any other baseline that needs to be preserved in the recovered signal.
Usage
set.SB(data, SB=NA, n.atoms=NA, scatter.length=NA, ADP=NA,
fit=FALSE, oneADP=TRUE, ADP.lim = c(0, 0.05))
Arguments
data |
an object of type |
SB |
numeric vector which, if not |
n.atoms , scatter.length , ADP |
numerics. Specify the number of atoms of each atomtype in the unit cell, atomic scattering factors and atomic displacement parameters (ADP), respectively. |
fit |
logical, whether to fit ADP. |
oneADP |
logical. If |
ADP.lim |
numeric vector that specifies the lower and upper bounds for the fitted ADP. |
Details
Baseline SB
has to be specified. If no baseline is needed fill SB
with zeroes. If n.atoms, scatter.length
and ADP
parameters are specified, the baseline is calculated according to
SB(x) = 1 - \frac{ \sum_i{N_i f_i^2 e^{-ADP_i x^2}} }{ N<f^2> }(1 - \frac{<f>^2-<f^2>}{<f>^2}).
If ADP
parameters are to be fitted, indicate n.atoms
, scatter.length
and set parameter fit
to TRUE
. Set oneADP
to the desired value.
Value
An object of type data
. Element
SB |
numeric vector containing the baseline. |
is replaced with its new value. Element
fitADP |
a list of values. |
might be added to describe the fit details.