resample.twotheta: Resample an XRD Pattern
In aqp: Algorithms for Quantitative Pedology

Description Usage Arguments Details Value Author(s) References See Also Examples

Resample an XRD pattern along a user-defined twotheta resolution via local spline interpolation.

1 2	resample.twotheta(twotheta, x, tt.min = min(twotheta), tt.max = max(twotheta), new.res = 0.02)

`twotheta`	a vector of twotheta value
`x`	a vector of diffraction intensities corresponding with twotheta values
`tt.min`	new minimum twotheta value, defaults to current minimum
`tt.max`	new maximum twotheta value, defaults to current maximum
`new.res`	new twotheta resolution, defaults to 0.02

Sometimes XRD patterns are collected at different resolutions, or at a resolution that is too great for full pattern matching. This function can be used to resample patterns to a consistent twotheta resolution, or to decimate massive patterns.

A dataframe with the following columns

`twotheta`	new sequence of twotheta values
`x`	resampled diffraction intensities

Dylan E Beaudette

http://casoilresource.lawr.ucdavis.edu/

rruff.sample

data(rruff.sample)

# resample single pattern
nontronite.resamp <- with(rruff.sample, 
resample.twotheta(twotheta, nontronite, new.res=0.02) )

# plot original vs. resampled pattern
plot(nontronite ~ twotheta, data=rruff.sample, type='l', col='grey')
lines(nontronite.resamp, col='blue')