align_xy.multiXY {powdR}

Align XRPD data in a multiXY object to a given standard

Description

align_xy.multiXY takes a multiXY object and aligns each of the XY data frames within it to a given standard. An optimisation routine is used that computes a suitable linear shift. After all samples have been aligned, the function harmonises the data to a single 2theta scale.

Usage

## S3 method for class 'multiXY'
align_xy(x, std, xmin, xmax, xshift, ...)

Arguments

x

a multiXY object.

std

a dataframe of the chosen standard that each sample will be aligned to (column 1 = 2theta, column 2 = counts)

xmin

the minimum 2theta value used during alignment

xmax

the maximum 2theta value used during alignment

xshift

the maximum (positive and negative) 2theta shift that is allowed during alignment

...

other arguments

Value

a multiXY object.

Examples

# Load soils xrd data
data(soils)

#Load minerals library
data(minerals)

## Not run: 
#Create a standard quartz pattern to align to
quartz <- data.frame(tth = minerals$tth,
                     counts = minerals$xrd$QUA.1)

#Plot the main quartz peak prior to alignment
plot(soils, wavelength = "Cu",
     xlim = c(26,27),
     normalise = TRUE)

#align data
aligned <- align_xy(soils,
                    std = quartz,
                    xmin = 10,
                    xmax = 60,
                    xshift = 0.2)

#replot data
plot(aligned, wavelength = "Cu",
     xlim = c(26,27),
     normalise = TRUE)


## End(Not run)