Package 'itraxR'

Itrax core scanner data for core CD166_19_S1

Description

A dataset containing XRF, optical and radiographic images and metadata for ocean core CD166_19_S1. This is a subset of a more complete dataset available.

Usage

CD166_19_S1

Format

A list containing the following:

xrf

a tibble of scan variables

rgb

a list containing the optical image matrix and associated metadata

rad

a list containing the radiographic image matrix and associated metadata

Source

Bishop, Thomas; Charidemou, Miros (2023): Core Scanning Data from Core CD166/19. PANGAEA, https://doi.pangaea.de/10.1594/PANGAEA.955347

---

Calculate a correlation matrix for Itrax result data

Description

Calculates a correlation matrix for Itrax data results including normalisation and visualisation

Usage

itrax_correlation(
  dataframe,
  elementsonly = TRUE,
  zeros = "addone",
  transform = TRUE,
  plot = FALSE
)

Arguments

dataframe	pass the name of a dataframe parsed using "itrax_import()" or "itrax_join()"
elementsonly	if TRUE, only chemical elements are included. If FALSE, the data is passed unfiltered, otherwise a character vector of desired variable names can be supplied
zeros	if "addone", adds one to all values. If "limit", replaces zero values with 0.001. Otherwise a function can be supplied to remove zero values.
transform	binary operator that if TRUE will center-log-transform the data, if FALSE will leave the data untransformed. Otherwise, a function can be supplied to transform the data.
plot	set to true if a biplot is required as a side-effect

Value

a correlation matrix object

Examples

itrax_correlation(CD166_19_S1$xrf, plot = TRUE)

---

Read an Itrax Image File

Description

Reads an Itrax image file and trims it according to the metadata provided.

Usage

itrax_image(
  file = "optical.tif",
  meta = "document.txt",
  plot = FALSE,
  trim = TRUE
)

Arguments

file	defines the name of the datafile to parse
meta	defines the relating metadata
plot	would you like to create a plot as a side-effect?
trim	defines custom trim parameters. The default behaviour uses the limits from the metadata file. Set the false for no trimming, or set the position limits by passing a two element vector.

Value

a matrix of RGB values, and the relevant data from the metadata file relating to the image.

Examples

itrax_image(file = system.file("extdata",
                         "CD166_19_S1_optical_lowres.tif",
                         package = "itraxR",
                         mustWork = TRUE),
            meta = system.file("extdata",
                         "CD166_19_S1_xrf_document.txt",
                         package = "itraxR",
                         mustWork = TRUE),
            plot = TRUE)

---

Import Itrax core-scanner result file

Description

Imports and parses data from a results file created by Q-Spec software, part of the Itrax core scanner.

Usage

itrax_import(
  filename = "Results.txt",
  depth_top = NA,
  trim_top = 0,
  trim_bottom = 0,
  parameters = "some"
)

Arguments

filename	defines the name of the datafile to parse
depth_top	defines the coring in depth of the top of the core, in mm
trim_top	defines the length of any trimming required of data at the top of the core, in mm
trim_bottom	defines the length of any trimming required at the bottom of the core, in mm
parameters	one of 'all' (leave all parameters), 'some' (remove some less useful parameters)

Value

a tibble of the parsed Itrax data

Examples

itrax_import(
  filename = system.file("extdata",
                         "CD166_19_S1_Results.txt",
                         package = "itraxR",
                         mustWork = TRUE),
  depth_top = 0)

---

Join two or more Itrax result datasets

Description

Join two or more Itrax datasets that have been parsed using "itrax_import()"

Usage

itrax_join(list)

Arguments

list	a list of dataframes that are parsed Itrax result files — this should have been imported using "itrax_import()" and must have a depth variable present. This should take the form "list(core1 = core1, core2 = core2)"

Value

a tibble of all the input data

Examples

itrax_join(list(core1 = CD166_19_S1$xrf, core2 = CD166_19_S1$xrf))

---

Parse Itrax scan metadata

Description

Parses the "document.txt files" generated from Itrax core scanners

Usage

itrax_meta(datafile = "document.txt")

Arguments

datafile

a "document.txt files" generated from an Itrax core scanner

Value

a dataframe of all the parsed input data

Examples

itrax_meta(system.file("extdata",
                       "CD166_19_S1_xrf_document.txt",
                       package = "itraxR",
                       mustWork = TRUE))

---

Convert an Itrax Image File into Munsell Colour

Description

Reads a colour calibrated Itrax image file and processes it to estimate Munsell colour.

Usage

itrax_munsell(image, proportion = 0.1)

Arguments

image	defines the name of the image file imported using 'itrax_image()'. It is essential that the image has been colour calibrated using a colour card or other method.
proportion	defines the width down the centre of the image to use for processing

Value

a table of values

Examples

## Not run: 
itrax_image(file = system.file("extdata",
                              "CD166_19_S1_optical_lowres.tif",
                              package = "itraxR",
                              mustWork = TRUE),
           meta = system.file("extdata",
                              "CD166_19_S1_xrf_document.txt",
                              package = "itraxR",
                              mustWork = TRUE),
           plot = FALSE) %>%
 magrittr::extract2(1) %>%
 itrax_munsell() %>%
 dplyr::slice_sample(n = 10)
 
## End(Not run)

---

Principle Component Analysis on Itrax scan data

Description

Performs and visualises principle component analysis data from Itrax result data

Usage

itrax_ordination(
  dataframe,
  elementsonly = TRUE,
  zeros = "addone",
  transform = TRUE,
  return = "list",
  plot = FALSE
)

Arguments

dataframe	pass the name of a dataframe parsed using "itrax_import()" or "itrax_join()"
elementsonly	if TRUE, only chemical elements are included. If FALSE, the data is passed unfiltered, otherwise a character vector of desired variable names can be supplied
zeros	if "addone", adds one to all values. If "limit", replaces zero values with 0.001. Otherwise a function can be supplied to remove zero values.
transform	binary operator that if TRUE will center-log-transform the data, if FALSE will leave the data untransformed. Otherwise, a function can be supplied to transform the data.
return	if "pca" the output of prcomp() is returned, otherwise "list" is a list including the transformed data, sample scores, and the output of prcomp().
plot	set to true if a biplot is required as a side-effect

Value

either an output of prcomp(), or a list including the input data

Examples

itrax_ordination(CD166_19_S1$xrf, plot = TRUE)

---

Read a Q-Spec settings file and parse the key-value pairs

Description

This is used to retrieve settings important elsewhere, for example the mca bin width and offset

Usage

itrax_qspecsettings(filename = "Results_settings.dfl")

Arguments

filename

the *.dfl settings file that relates to the rest of the data

Value

a tibble of the parsed data

Examples

itrax_qspecsettings(filename = system.file("extdata",
                                "Results_settings.dfl",
                                package = "itraxR",
                                mustWork = TRUE)
                                )

---

Read an Itrax Radiograph File

Description

Reads an Itrax radiograph file and trims it according to the metadata provided.

Usage

itrax_radiograph(
  file = "radiograph.tif",
  meta = "document.txt",
  plot = FALSE,
  trim = TRUE
)

Arguments

file	defines the name of the datafile to parse
meta	defines the relating metadata
plot	would you like to create a plot as a side-effect?
trim	defines positions of the trim if required, input is a vector with min and max positions

Value

a matrix of RGB values, and the relevant data from the metadata file relating to the image. Also computes the aspect ratio of the image.

Examples

itrax_radiograph(file = system.file("extdata",
                         "CD166_19_S1_radiograph_adj.tif",
                         package = "itraxR",
                         mustWork = TRUE),
                 meta = system.file("extdata",
                         "CD166_19_S1_rad_document.txt",
                         package = "itraxR",
                         mustWork = TRUE),
                 plot = TRUE)

---

Reduce Itrax XRF data

Description

Reduces Itrax XRF data into arbitrary chunks using an arbitrary function. This is useful when making direct comparisons between the Itrax XRF data and some other data collected at a lower resolution.

Usage

itrax_reduce(
  dataframe,
  names = c(1:length(breaks_lower)),
  breaks_lower,
  breaks_upper,
  fun = mean,
  edges = c(">=", "<"),
  by = NULL
)

Arguments

dataframe	defines the name of the XRF data to reduce, usually a itraxR::itrax_import like tibble
names	optional, a vector of the same length as 'breaks'
breaks_lower	a vector of the lower limit of each chunk
breaks_upper	a vector of the upper limit of each chunk
fun	the function to apply in order to reduce the data. Default is mean(), but sd() is also common
edges	a vector of length 2 with the upper and lower bound behaviour; can be any of '<', '<=', '>', '>='
by	if contiguous samples of even sizes are required, 'by' defines the chunk size and will automatically generate 'breaks'

Value

a tibble with the same number of rows as 'breaks' and the same number of columns as 'dataframe'

Examples

itrax_reduce(dataframe = CD166_19_S1$xrf, by = 10)

---

Make a spectrograph from raw Itrax data spectra files

Description

Parses a folder full of raw spectra files from an Itrax core scanner and produces a spectral graph of all the data by position

Usage

itrax_restspectra(
  foldername = "XRF data",
  parameters = "settings.dfl",
  datapos = 37,
  depthpos = 6,
  plot = TRUE,
  trans = "pseudo_log"
)

Arguments

foldername	defines the folder where the spectra "*.spe" files are located - or the path of the zipped folder where it is stored.
parameters	optionally, defines the Q-Spec settings file from which to calculate the channel energies
datapos	defines the row at which spectral data begins in the files
depthpos	defines the row at which depth data begins is located in the files
plot	TRUE/FALSE, selects whether to create a plot as a side-effect
trans	transformation applied in the plot - see '?ggplot2::scales_colour_gradient()' for options

Value

a dataframe of all the spectral data

Examples

## Not run: itrax_restspectra("~/itraxBook/CD166_19_(2020)/CD166_19_S1/CD166_19_S1/XRF data")

---

Cluster analysis and statistical grouping of Itrax data

Description

Performs a cluster analysis and automatic statistical grouping of parsed Itrax results data to n groups. Also provides information on the most "representative" (central) of each group. These can be used to develop a sub-sampling regime for calibration using another method.

Usage

itrax_section(
  dataframe,
  divisions = 30,
  elementsonly = TRUE,
  zeros = "addone",
  transform = TRUE,
  plot = FALSE
)

Arguments

dataframe	pass the name of a dataframe parsed using "itrax_import()" or "itrax_join()" or "itrax_reduce()".
divisions	the number of groups to slice into - also the number of representative samples returned.
elementsonly	if TRUE, only chemical elements are included. If FALSE, the data is passed unfiltered, otherwise a character vector of desired variable names can be supplied.
zeros	if "addone", adds one to all values. If "limit", replaces zero values with 0.001. Otherwise a function can be supplied to remove zero values.
transform	binary operator that if TRUE will center-log-transform the data, if FALSE will leave the data untransformed. Otherwise, a function can be supplied to transform the data.
plot	set to true if a summary plot is required as a side-effect - the input dataset must have a depth or position variable - depth is used preferentially.

Value

the input data with additional columns 'group' and 'calib_sample', and possibly 'uid' if not supplied.

Examples

itrax_section(CD166_19_S1$xrf, plot = TRUE)
itrax_section(CD166_19_S1$xrf %>% itrax_reduce(by = 10), plot = TRUE)

---

Import an individual spectra file

Description

Sometimes it is helpful to read an individual spectral file for diagnostics

Usage

itrax_spectra(filename, parameters = "settings.dfl", plot = TRUE, datapos = 37)

Arguments

filename	defines the name of the *.spe datafile from the core scanner to parse
parameters	optionally defines a relevant Q-Spec settings file in order to compute the energy scale, otherwise channel numbers are reported
plot	logical, if TRUE a side-plot is created
datapos	defines the row at which spectral data begins in the files

Value

a tibble of the parsed data

Examples

itrax_spectra(filename   = system.file("extdata",
                                      "L000676.spe",
                                      package = "itraxR",
                                      mustWork = TRUE),
               parameters = system.file("extdata",
                                        "Results_settings.dfl",
                                        package = "itraxR",
                                        mustWork = TRUE)
               )

---