RSSLine {nanop}R Documentation

Function to generate 1-D RSS Lines

Description

Function to generate 1-D RSS lines that represent the residual sum of squares as a single parameter (r, rcore or latticep) is varied.

Usage

RSSLine(ref,  rcore, sigc, sigs, r, latticep=4.08, 
                    calpha=1, dr=.01, minR=1, maxR=20, p = 1,
                    dQ=.01, minQ=1,maxQ=20, a1 = 16.8819,
                    b1=.4611, a2=18.5913, b2=8.6216,
                    a3=25.5582, b3=1.48260, a4=5.86, b4=36.3956,
                    c=12.0658, calcPDF=TRUE, calcScatt=TRUE, norm=TRUE,
                    avRes = 1, rcenter=TRUE) 

Arguments

Only one of r, rcore, latticep can have length greater than 1; the vector with length greater than 1 represents the values over which to evaluate the RSS, with the other parameters fixed. The argument ref indicates the value of the varied parameter to use in simulation of the data.

ref numeric value indicating the value of the varied parameter to be used in simulating the data.
rcore either a single numeric value or a vector of numeric values for the parameter rcore
sigc a single numeric value for the parameter sigc
sigs a single numeric value for the parameter sigs
r either a single numeric value or a vector of numeric values for the parameter r
latticep either a single numeric value or a vector of numeric values for the parameter latticep
dr numeric indicating the step size in r desired
minR numeric indicating the minimum value of r for which the function should be evaluated
maxR numeric indicating the maximum value of r for which the function should be evaluated
p numeric indicating the atomic number density or an approximation thereof
dQ numeric indicating the step size in Q desired
minQ numeric indicating the minimum value of Q for which the function should be evaluated
maxQ numeric indicating the maximum value of Q for which the function should be evaluated
a1 numeric X-ray scattering factor parameter; see details
b1 numeric X-ray scattering factor parameter; see details
a2 numeric X-ray scattering factor parameter; see details
b2 numeric X-ray scattering factor parameter; see details
a3 numeric X-ray scattering factor parameter; see details
b3 numeric X-ray scattering factor parameter; see details
a4 numeric X-ray scattering factor parameter; see details
b4 numeric X-ray scattering factor parameter; see details
c numeric X-ray scattering factor parameter; see details
avRes numeric (integer) giving the ensemble size used to calculate both the data and the model
rcenter logical indication whether center should be chosen at random within the unit cell; note that use of a random center results in more computational time, since particle positions are not recycled
calpha numeric scaling factor for PDF determination
calcPDF logical indicating whether the RSS line should be determined for a PDF model
calcScatt logical indicating whether the RSS line should be determined for a total scattering structure function model
norm logical indicating whether the results should be normalized

Details

The X-ray scattering factor is approximated by the function f(s)=a_1 * exp(-b_1 s) + a_2 * exp(-b_2 s) + a_3 * exp(-b_3 s) + a_4 * exp(-b_4 s) + c with s = \frac{Q}{4\pi}. The constants in the function are possible to specify as arguments. Their default values correspond to the values for Au.

Value

List in which the first element are the values of the parameter that is varied, and additional elements

ansR numeric vector of values at which the RSS was evaluated for the PDF RSS function
ansQ numeric vector of values at which the RSS was evaluated for the total scattering structure function RSS function

See Also

simPart, displacePart


[Package nanop version 1.0 Index]