aqp (version 1.32)

resample.twotheta: Resample an XRD Pattern

Description

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

Usage

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

Arguments

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

Value

A dataframe with the following columns

twotheta

new sequence of twotheta values

x

resampled diffraction intensities

Details

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.

References

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

See Also

rruff.sample

Examples

# NOT RUN {
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')

# }