Calculate and plot the Pair Distribution Function

Share:

Description

Calculates and plots the corrected Pair Distribution Function.

Usage

1
2
calc.Gr(fit.results, rho.0, plot=TRUE, r.min = 0, r.max = 5, 
        dr = 0.01, Q.min = NA, Q.max = NA, nsd = 2, gr.compare=NA)

Arguments

fit.results

the return value of do.fit.

plot

logical, whether to plot the PDF.

rho.0

numeric, the atomic number density of the material: the number of atoms per unit cell divided by a volume of the unit cell.

r.min, r.max, dr

numerics. Function is plotted in the region [r.min, r.max].

Q.min, Q.max

numerics. To calculate the sine-Fourier transform, the total scattering function S(Q) is "terminated" at a certain Q=Qmax point. The best Qmax point to terminate S(Q) (that corresponds to the value of S(Q)-1 closest to zero) is sought in the [Q.min,Q.max] region.

nsd

numeric, the number of standard deviations to plot the uncertainty.

gr.compare

numeric vector. If not NA, specifies the function to add to the plot. Should correspond to the same grid ([r.min, r.max, dr]).

Details

The function uses ggplot2 package for plotting. ggplot2 package can be installed by typing install.packges("ggplot2").

Value

A list with elements:

r

numeric vector of grid points

gr

numeric vector, indicates the corrected Pair Distribution Function.

stdev

numeric vector, indicates estimated standard deviation.

See Also

do.fit