Completely reworked electrochemical scale converter

by adding a new family of functions.
Corrected package version number to dev. A few other smaller (older) changes.

DESCRIPTION

@@ -1,7 +1,7 @@
 Package: common
 Type: Package
 Title: chepec common
-Version: 0.1.0
+Version: 0.0.0.9000
 Description: Commonly used functions and scripts.
 Authors@R: person("Taha", "Ahmed", email = "taha@chepec.se", role = c("aut", "cre"))
 License: GPL-3

NAMESPACE

@@ -3,6 +3,7 @@
 export(AVS2SHE)
 export(Celsius2Kelvin)
 export(ConvertRefPot)
+export(ExtractSampleIdString)
 export(GenericXtableSetAttributes)
 export(Kelvin2Celsius)
 export(LoadRData2Variable)
@@ -12,12 +13,14 @@ export(SHE2AVS)
 export(SubfigureGenerator)
 export(SubstrateHistory)
 export(TabularXtableHeader)
+export(as.SHE)
 export(as.degrees)
 export(as.radians)
 export(int2padstr)
 export(is.wholenumber)
 export(molarity2mass)
 export(numbers2words)
+export(potentials.as.SHE)
 export(roundup)
 export(siunitx.uncertainty)
 export(thth2d)

R/samples.R

@@ -27,6 +27,28 @@ ProvideSampleId <- function (pathexpfile, implementation = "filename") {
 }
 
 
+
+#' Extract sampleid from a string
+#'
+#' Extract sampleid from a string by utilising the fact that samepleid's
+#' adhere to a defined format.
+#'
+#' @param string character string that contains a sampleid
+#'
+#' @return sampleid (character string)
+#' @export
+ExtractSampleIdString <- function(string) {
+   # regmatches() extracts matched substrings based on the results of regexpr and friends
+   # another way to do this would be stringr::str_extract()
+   sampleid <-
+      regmatches(string, regexpr("\\d{1,2}[A-Za-z]{1}\\d{2,4}", string))
+   # return empty string rather than character(0)
+   if (length(sampleid) == 0) sampleid <- ""
+   return(sampleid)
+}
+
+
+
 #' Display the history of a substrate (sampleid)
 #'
 #' @param sampleid    string

R/unit-converters-electrochemical.R

@@ -26,13 +26,326 @@ SHE2AVS <- function(she) {
 }
 
 
+
+#' Get standardised name of reference electrode
+#'
+#' Given a reference electrode label, this function returns its canonical name
+#' (as defined by this package).
+#' This function tries to match against as many variations as possible for each
+#' reference electrode.
+#'
+#' @param refname string
+#'
+#' @return the canonical name or empty string
+RefCanonicalName <- function(refname) {
+   # scale names
+   electrode.system <- list()
+   electrode.system[["SHE"]] <-
+      c("SHE",
+        "standard hydrogen",
+        "standard hydrogen electrode")
+   electrode.system[["AgCl/Ag"]] <-
+      c("AgCl/Ag",
+        "Ag/AgCl",
+        "AgCl",
+        "silver-silver chloride",
+        "silver chloride",
+        "SSC") # saturated silver-silver chloride is sometimes abbreviated SSC
+   electrode.system[["Hg2Cl2/Hg"]] <-
+      c("Hg2Cl2/Hg",
+        "Hg/Hg2Cl2",
+        "Hg2Cl2",
+        "calomel-mercury",
+        "mercury-calomel",
+        "SCE")
+   electrode.system[["AVS"]] <-
+      c("AVS",
+        "vacuum",
+        "vacuum scale",
+        "absolute",
+        "absolute scale",
+        "absolute vacuum scale")
+   electrode.system[["Li"]] <-
+      c("Li",
+        "Li/Li+",
+        "Lithium")
+
+   # to match the lowercase version, use tolower()
+   # perhaps also replace hyphens and slashes with space?
+
+   matches <-
+      data.frame(electrode = names(electrode.system),
+                 m = rep(0, length(electrode.system)),
+                 stringsAsFactors = FALSE)
+
+   # loop over electrode systems
+   for (i in 1:length(electrode.system)) {
+      # check for a match in any cell of this row,
+      # also trying all lower-case and substituting symbols with spaces
+      if (any(electrode.system[[i]] == refname) ||
+          any(tolower(electrode.system[[i]]) == refname) ||
+          any(gsub("[-/]", " ", electrode.system[[i]]) == refname)) {
+         matches$m[i] <- 1
+      }
+   }
+
+   # if everything went as expected we should have just one match
+   if (sum(matches$m) != 1) {
+      # something wrong (should probably add warn/error here)
+      # for now, just return empty string
+      return("")
+   } else {
+      return(matches$electrode[which(matches$m == 1)])
+   }
+}
+
+
+
+
+#' Potentials as SHE
+#'
+#' This function just outputs a tidy dataframe with potential vs SHE for
+#' different scales, electrolytes, concentrations, and temperatures.
+#' Using data from literature.
+#'
+#' @return tidy dataframe with the following columns
+#'    \tabular{ll}{
+#'    \code{electrode}     \tab reference electrode \cr
+#'    \code{electrolyte}   \tab electrolyte \cr
+#'    \code{conc.num}      \tab concentration of electrolyte, mol/L \cr
+#'    \code{conc.string}   \tab concentration of electrolyte, as string, may also note temperature at which conc \cr
+#'    \code{temp}          \tab temperature / degrees Celsius \cr
+#'    \code{SHE}           \tab potential vs SHE / volt \cr
+#'    \code{sid}           \tab set id, just for housekeeping inside this function \cr
+#'    \code{reference}     \tab BibTeX reference \cr
+#'    \code{dEdT}          \tab temperature coefficient / volt/kelvin \cr
+#'    }
+#' @export
+potentials.as.SHE <- function() {
+   # scale name should be one of canonical (see RefCanonicalName)
+
+   # follow the convention of "each row one observation" (at different temperatures)
+   # all potentials vs SHE
+
+   potentials <-
+      as.data.frame(matrix(data =
+                              # electrode # electrolyte # conc/M # conc label # temp # pot vs SHE # set id # ref
+                              c("AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "10", "0.215", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "15", "0.212", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "20", "0.208", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "25", "0.205", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "30", "0.201", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "35", "0.197", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "3.5", "3.5M at 25C", "40", "0.193", "1", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "10", "0.214", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "15", "0.209", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "20", "0.204", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "25", "0.199", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "30", "0.194", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "35", "0.189", "2", "Sawyer1995",
+                                "AgCl/Ag",   "KCl(aq)", "4.2", "saturated",   "40", "0.184", "2", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "10", "0.336", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "15", "0.336", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "20", "0.336", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "25", "0.336", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "30", "0.335", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "35", "0.334", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "0.1", "0.1M at 25C", "40", "0.334", "3", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "1.0", "1.0M at 25C", "10", "0.287", "4", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "1.0", "1.0M at 25C", "20", "0.284", "4", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "1.0", "1.0M at 25C", "25", "0.283", "4", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "1.0", "1.0M at 25C", "30", "0.282", "4", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "1.0", "1.0M at 25C", "40", "0.278", "4", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "10", "0.256", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "15", "0.254", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "20", "0.252", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "25", "0.250", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "30", "0.248", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "35", "0.246", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "3.5", "3.5M at 25C", "40", "0.244", "5", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "10", "0.254", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "15", "0.251", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "20", "0.248", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "25", "0.244", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "30", "0.241", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "35", "0.238", "6", "Sawyer1995",
+                                "Hg2Cl2/Hg", "KCl(aq)", "4.2", "saturated",   "40", "0.234", "6", "Sawyer1995",
+                                "AVS",       "",        "",     "",           "25", "-4.44", "7", "Trasatti1986"),
+                           ncol = 8,
+                           byrow = TRUE), stringsAsFactors = FALSE)
+
+   colnames(potentials) <-
+      c("electrode",
+        "electrolyte",
+        "conc.num",
+        "conc.string",
+        "temp",
+        "SHE",
+        "sid",
+        "reference")
+
+   # convert these columns to type numeric
+   potentials[, c("conc.num", "temp", "SHE")] <-
+      as.numeric(as.character(unlist(potentials[, c("conc.num", "temp", "SHE")])))
+
+   # make room for a dE/dT column
+   potentials$dEdT <- as.numeric(NA)
+
+   # calculate temperature coefficient (dE/dT) for each scale and concentration (ie. set id)
+   for (s in 1:length(unique(potentials$sid))) {
+      # sid column eas added to data just to make this calculation here easier
+      subspot <- potentials[which(potentials$sid == unique(potentials$sid)[s]), ]
+      # a linear fit will give us temperature coefficient as slope
+      lm.subspot <- stats::lm(SHE ~ temp, data = subspot)
+      potentials[which(potentials$sid == unique(potentials$sid)[s]), "dEdT"] <-
+         lm.subspot$coefficients[2]
+   }
+
+   return(potentials)
+}
+
+
+
+
+#' Convert from electrochemical or electronic scale to SHE
+#'
+#' @param potential in the original scale, V or eV
+#' @param scale name of the original scale
+#' @param concentration of electrolyte in mol/L, or as the string "saturated"
+#' @param temperature of system in degrees Celsius
+#' @param as.SHE.data dataframe with dataset
+#'
+#' @return potential in SHE scale
+#' @export
+as.SHE <- function(potential,
+                   scale,
+                   concentration = "saturated",
+                   temperature = 25,
+                   as.SHE.data = potentials.as.SHE()) {
+
+   # if the supplied temperature does not exist in the data, this function will attempt to interpolate
+   # note that concentration has to match, no interpolation is attempted for conc
+
+   if (RefCanonicalName(scale) == "") {
+      warning("as.SHE(): Sorry, you have supplied an unrecognised electrode scale.")
+      return(NA)
+   }
+
+   # there is the simple case of
+   if (RefCanonicalName(scale) == "SHE") {
+      warning("This function can only convert from scales other than SHE!")
+      return(NA)
+   }
+
+   # AVS needs special consideration
+   if (RefCanonicalName(scale) == "AVS") {
+      # reset arg concentration
+      concentration <- ""
+      # second, since AVS scale goes in the opposite direction to the electrochemical scales
+      # we will define our own function
+      negifavs <- function(a, b) {
+         a - b
+      }
+   } else {
+      # we will define the same function differently for
+      # the case we're not dealing with AVS
+      negifavs <- function(a, b) {
+         a + b
+      }
+   }
+
+   if (is.character(concentration)) {
+      # supplied concentration is character string
+      subspot <-
+         subset(subset(as.SHE.data,
+                       electrode == RefCanonicalName(scale)),
+                conc.string == concentration)
+      # if either "scale" or "concentration" are not found in the data, subspot will contain zero rows
+      if (dim(subspot)[1] == 0) {
+         warning("as.SHE(): Supplied scale or concentration does not exist in data. Returning NA.")
+         return(NA)
+      }
+      # so far, we have
+      # scale: checked!
+      # concentration: checked!
+      # only temperature remains to be handled
+      # temperature value could happen to match a value in the data, or lie somewhere in between
+      # note: we will not allow extrapolation
+      if (!any(subspot$temp == temperature)) {
+         # if sought temperature is not available in dataset, check that it falls inside
+         if ((temperature < max(subspot$temp)) && (temperature > min(subspot$temp))) {
+            # within dataset range, do linear interpolation
+            lm.subspot <- stats::lm(SHE ~ temp, data = subspot)
+            # interpolated temperature, calculated based on linear regression
+            # (more accurate than simple linear interpolation with approx())
+            potinterp <-
+               lm.subspot$coefficients[2] * temperature + lm.subspot$coefficients[1]
+            ### CALC RETURN POTENTIAL
+            return(negifavs(potinterp, potential))
+         } else {
+            # outside dataset range, warning and return NA (we don't extrapolate)
+            warning("as.SHE(): the temperature you requested falls outside data range.")
+            return(NA)
+         }
+      } else {
+         # requested temperature does exist in dataset
+         ### CALC RETURN POTENTIAL
+         return(negifavs(subset(subspot, temp == temperature)$SHE, potential))
+      }
+   # outer-most if-else
+   } else {
+      # supplied concentration is numeric
+      # note: all code inside this else is the same as inside the if,
+      # just for the case of numeric concentration
+      subspot <-
+         subset(subset(as.SHE.data,
+                       electrode == RefCanonicalName(scale)),
+                conc.num == concentration)
+      # if either "scale" or "concentration" are not found in the data, subspot will contain zero rows
+      if (dim(subspot)[1] == 0) {
+         warning("as.SHE(): Supplied scale or concentration does not exist in data. Returning NA.")
+         return(NA)
+      }
+      if (!any(subspot$temp == temperature)) {
+         # if sought temperature is not available in dataset, check that it falls inside
+         if ((temperature < max(subspot$temp)) && (temperature > min(subspot$temp))) {
+            # within dataset range, do linear interpolation
+            lm.subspot <- stats::lm(SHE ~ temp, data = subspot)
+            # interpolated temperature, calculated based on linear regression
+            # (more accurate than simple linear interpolation with approx())
+            potinterp <-
+               lm.subspot$coefficients[2] * temperature + lm.subspot$coefficients[1]
+            ### CALC RETURN POTENTIAL
+            return(negifavs(potinterp, potential))
+         } else {
+            # outside dataset range, warning and return NA (we don't extrapolate)
+            warning("as.SHE(): the temperature you requested falls outside data range.")
+            return(NA)
+         }
+      } else {
+         # requested temperature does exist in dataset
+         ### CALC RETURN POTENTIAL
+         return(negifavs(subset(subspot, temp == temperature)$SHE, potential))
+      }
+
+   }
+}
+
+
+
+
+
+
+
+
+
 #' ConvertRefPotEC
 #'
 #' This function does the heavy lifting.
 #' Converts from an electrochemical reference scale into another.
-#' SHE:     standard hydrogen electrode scale
+#' SHE:     standard hydrogen electrode
-#' Ag/AgCl: silver silver-chloride electrode scale (3M KCl)
+#' Ag/AgCl: silver silver-chloride electrode (3M KCl)
-#' SCE:     standard calomel scale
+#' SCE:     saturated calomel electrode
 #'
 #' @param argpotential    potential (numeric)
 #' @param argrefscale     input reference scale (character string)
@@ -46,7 +359,10 @@ ConvertRefPotEC <- function(argpotential, argrefscale, valuerefscale) {
    refcolnames     <- c("SHE0",   "AgCl0", "SCE0",    "Li0")
    ##### Add more reference electrodes here <<
    #
-   SHE0 <- data.frame(matrix(refpotatSHEzero, ncol=length(refpotatSHEzero), byrow=T))
+   SHE0 <-
+      data.frame(matrix(refpotatSHEzero,
+                        ncol = length(refpotatSHEzero),
+                        byrow = T))
    refpotmtx <- matrix(NA, length(SHE0), length(SHE0))
    refpotmtx[,1] <- matrix(as.matrix(SHE0), ncol = 1, byrow = T)
    for (c in 2:length(SHE0)) {
@@ -93,6 +409,11 @@ ConvertRefPot <- function(argpotential, argrefscale, valuerefscale) {
 
    #  IDEA: make a matrix out of these (scale names and flags)
 
+
+
+
+
+
    # Valid scales
    scale.names <- list()
    scale.names[["SHE"]] <- c("SHE", "NHE", "she", "nhe")
@@ -102,7 +423,10 @@ ConvertRefPot <- function(argpotential, argrefscale, valuerefscale) {
    scale.names[["AVS"]] <- c("AVS", "avs")
 
    # Set flags
-   bool.flags <- as.data.frame(matrix(0, nrow = length(scale.names), ncol = 2))
+   bool.flags <-
+      as.data.frame(matrix(0,
+                           nrow = length(scale.names),
+                           ncol = 2))
    names(bool.flags) <- c("argref", "valueref")
    row.names(bool.flags) <- names(scale.names)
 
@@ -110,6 +434,10 @@ ConvertRefPot <- function(argpotential, argrefscale, valuerefscale) {
    # Check that argrefscale is valid character mode
    # ...
 
+   # steps through all scale names, "row-by-row",
+   # looking for any cell matching "argrefscale" string
+   # if found, save the position of that refelectrode (in scale.names) to
+   # that row and "argref" column of bool.flags
    for (j in 1:length(row.names(bool.flags))) {
       if (any(scale.names[[row.names(bool.flags)[j]]] == argrefscale)) {
          bool.flags[row.names(bool.flags)[j], "argref"] <- j

R/unit-converters.R

@@ -1,3 +1,33 @@
+# nm2eV <- function(nm) {
+#    ## Depends on:
+#    ## chepec/chetex/common/R/sunlight/solarconstants.R
+#    # Converts wavelength in nm to energy in eV
+#    #
+#    sun.constants <- solar.constants()
+#
+#    eV <-
+#       sun.constants["h.eV", "value"] *
+#       1E9 * sun.constants["c", "value"] / nm
+#
+#    return(eV)
+# }
+
+
+# eV2nm <- function(eV) {
+#    ## Depends on:
+#    ## chepec/chetex/common/R/sunlight/solarconstants.R
+#    # Converts energy in eV to wavelength in nm
+#    #
+#    sun.constants <- solar.constants()
+#
+#    nm <-
+#       sun.constants["h.eV", "value"] *
+#       1E9 * sun.constants["c", "value"] / eV
+#
+#    return(nm)
+# }
+
+
 #' Convert wavelength to wavenumber
 #'
 #' Converts wavelength (nm) to wavenumber (cm-1)

man/ConvertRefPotEC.Rd

@@ -19,8 +19,8 @@ potential in output reference scale (numeric)
 \description{
 This function does the heavy lifting.
 Converts from an electrochemical reference scale into another.
-SHE:     standard hydrogen electrode scale
+SHE:     standard hydrogen electrode
-Ag/AgCl: silver silver-chloride electrode scale (3M KCl)
+Ag/AgCl: silver silver-chloride electrode (3M KCl)
-SCE:     standard calomel scale
+SCE:     saturated calomel electrode
 }
 

man/ExtractSampleIdString.Rd

@@ -0,0 +1,19 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/samples.R
+\name{ExtractSampleIdString}
+\alias{ExtractSampleIdString}
+\title{Extract sampleid from a string}
+\usage{
+ExtractSampleIdString(string)
+}
+\arguments{
+\item{string}{character string that contains a sampleid}
+}
+\value{
+sampleid (character string)
+}
+\description{
+Extract sampleid from a string by utilising the fact that samepleid's
+adhere to a defined format.
+}
+

man/RefCanonicalName.Rd

@@ -0,0 +1,21 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/unit-converters-electrochemical.R
+\name{RefCanonicalName}
+\alias{RefCanonicalName}
+\title{Get standardised name of reference electrode}
+\usage{
+RefCanonicalName(refname)
+}
+\arguments{
+\item{refname}{string}
+}
+\value{
+the canonical name or empty string
+}
+\description{
+Given a reference electrode label, this function returns its canonical name
+(as defined by this package).
+This function tries to match against as many variations as possible for each
+reference electrode.
+}
+

man/as.SHE.Rd

@@ -0,0 +1,27 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/unit-converters-electrochemical.R
+\name{as.SHE}
+\alias{as.SHE}
+\title{Convert from electrochemical or electronic scale to SHE}
+\usage{
+as.SHE(potential, scale, concentration = "saturated", temperature = 25,
+  as.SHE.data = potentials.as.SHE())
+}
+\arguments{
+\item{potential}{in the original scale, V or eV}
+
+\item{scale}{name of the original scale}
+
+\item{concentration}{of electrolyte in mol/L, or as the string "saturated"}
+
+\item{temperature}{of system in degrees Celsius}
+
+\item{as.SHE.data}{dataframe with dataset}
+}
+\value{
+potential in SHE scale
+}
+\description{
+Convert from electrochemical or electronic scale to SHE
+}
+

man/potentials.as.SHE.Rd

@@ -0,0 +1,28 @@
+% Generated by roxygen2: do not edit by hand
+% Please edit documentation in R/unit-converters-electrochemical.R
+\name{potentials.as.SHE}
+\alias{potentials.as.SHE}
+\title{Potentials as SHE}
+\usage{
+potentials.as.SHE()
+}
+\value{
+tidy dataframe with the following columns
+   \tabular{ll}{
+   \code{electrode}     \tab reference electrode \cr
+   \code{electrolyte}   \tab electrolyte \cr
+   \code{conc.num}      \tab concentration of electrolyte, mol/L \cr
+   \code{conc.string}   \tab concentration of electrolyte, as string, may also note temperature at which conc \cr
+   \code{temp}          \tab temperature / degrees Celsius \cr
+   \code{SHE}           \tab potential vs SHE / volt \cr
+   \code{sid}           \tab set id, just for housekeeping inside this function \cr
+   \code{reference}     \tab BibTeX reference \cr
+   \code{dEdT}          \tab temperature coefficient / volt/kelvin \cr
+   }
+}
+\description{
+This function just outputs a tidy dataframe with potential vs SHE for
+different scales, electrolytes, concentrations, and temperatures.
+Using data from literature.
+}
+