From a94bd86465fe191102a2bf85a3631c83cd10db0a Mon Sep 17 00:00:00 2001 From: ranke Date: Tue, 15 Feb 2005 10:14:01 +0000 Subject: First import, for archiving purposes. git-svn-id: http://kriemhild.uft.uni-bremen.de/svn/chemCal@1 5fad18fb-23f0-0310-ab10-e59a3bee62b4 --- DESCRIPTION | 12 +++ INDEX | 10 +++ R/chemCal.R | 195 +++++++++++++++++++++++++++++++++++++++++++++++ chm/00Index.html | 26 +++++++ chm/Rchm.css | 25 ++++++ chm/calplot.html | 94 +++++++++++++++++++++++ chm/calpredict.html | 106 ++++++++++++++++++++++++++ chm/chemCal.chm | Bin 0 -> 25115 bytes chm/chemCal.hhp | 17 +++++ chm/chemCal.toc | 51 +++++++++++++ chm/din32645.html | 44 +++++++++++ chm/logo.jpg | Bin 0 -> 8793 bytes chm/pahCalibration.html | 48 ++++++++++++ data/din32645.rda | Bin 0 -> 453 bytes data/pahCalibration.rda | Bin 0 -> 1289 bytes data/pahMeasurements.rda | Bin 0 -> 1348 bytes man/calplot.Rd | 52 +++++++++++++ man/calpredict.Rd | 64 ++++++++++++++++ man/din32645.Rd | 15 ++++ man/multical.Rd | 37 +++++++++ man/pahCalibration.Rd | 19 +++++ man/pahMeasurements.Rd | 19 +++++ 22 files changed, 834 insertions(+) create mode 100644 DESCRIPTION create mode 100644 INDEX create mode 100644 R/chemCal.R create mode 100755 chm/00Index.html create mode 100755 chm/Rchm.css create mode 100755 chm/calplot.html create mode 100755 chm/calpredict.html create mode 100755 chm/chemCal.chm create mode 100755 chm/chemCal.hhp create mode 100755 chm/chemCal.toc create mode 100755 chm/din32645.html create mode 100755 chm/logo.jpg create mode 100755 chm/pahCalibration.html create mode 100644 data/din32645.rda create mode 100644 data/pahCalibration.rda create mode 100644 data/pahMeasurements.rda create mode 100644 man/calplot.Rd create mode 100644 man/calpredict.Rd create mode 100644 man/din32645.Rd create mode 100644 man/multical.Rd create mode 100644 man/pahCalibration.Rd create mode 100644 man/pahMeasurements.Rd diff --git a/DESCRIPTION b/DESCRIPTION new file mode 100644 index 0000000..18bcf09 --- /dev/null +++ b/DESCRIPTION @@ -0,0 +1,12 @@ +Package: chemCal +Version: 0.03-1 +Date: 2005-01-14 +Title: Calibration for analytical chemistry +Author: Johannes Ranke +Maintainer: Johannes Ranke +Depends: R +Description: chemCal provides simple functions for plotting + calibration functions and for estimating standard errors for measurements. +License: GPL version 2 or newer +URL: http://www.r-project.org, + http://www.uft.uni-bremen.de/chemie/ranke diff --git a/INDEX b/INDEX new file mode 100644 index 0000000..ec2f1b4 --- /dev/null +++ b/INDEX @@ -0,0 +1,10 @@ +calm Generate a linear calibration model +calplot Plot calibration graphs +plot.calm Plot prediction bands +calpredict Estimate measurement results including + confidence intervals +predict.calm Estimate measurement results including confidence + intervals +din32645 Calibration data from DIN 32645 +pahCalibration Calibration data for HPLC measurement of 4 PAH +pahMeasurements Measurement data for HPLC measurement of 4 PAH diff --git a/R/chemCal.R b/R/chemCal.R new file mode 100644 index 0000000..5de33f8 --- /dev/null +++ b/R/chemCal.R @@ -0,0 +1,195 @@ +calm <- function(data) +{ + y <- data[[2]] + x <- data[[1]] + m <- lm(y ~ x) + s <- summary(m) + if (s$coefficients[1,4] > 0.05) + { + m <- lm(y ~ x - 1) + s <- summary(m) + m$intercept <- FALSE + } else { + m$intercept <- TRUE + } + class(m) <- "calm" + m$yname <- names(data)[[1]] + m$xname <- names(data)[[2]] + return(m) +} +predict.calm <- predict.lm +print.calm <- print.lm +summary.calm <- summary.lm +plot.calm <- function(m, + xunit="",yunit="",measurand="", + level=0.95) +{ + x <- m$model$x + y <- m$model$y + newdata <- data.frame(x = seq(0,max(x),length=250)) + pred.lim <- predict(m, newdata, interval = "prediction",level=level) + conf.lim <- predict(m, newdata, interval = "confidence",level=level) + if (xunit!="") { + xlab <- paste("Concentration in ",xunit) + } else xlab <- m$xname + if (yunit=="") yunit <- m$yname + if (measurand!="") { + main <- paste("Calibration for",measurand) + } else main <- "Calibration" + plot(1, + xlab = xlab, + ylab = yunit, + type = "n", + main = main, + xlim = c(0,max(x)), + ylim = range(pred.lim) + ) + points(x,y, pch = 21, bg = "yellow") + matlines(newdata$x, pred.lim, lty = c(1, 4, 4), + col = c("black", "red", "red")) + matlines(newdata$x, conf.lim, lty = c(1, 3, 3), + col = c("black", "green4", "green4")) + + legend(min(x), + max(pred.lim, na.rm = TRUE), + legend = c("Fitted Line", "Confidence Bands", + "Prediction Bands"), + lty = c(1, 3, 4), + lwd = 2, + col = c("black", "green4", "red"), + horiz = FALSE, cex = 0.9, bg = "gray95") +} +predictx.calm <- function(m,measurements) +{ + s <- summary(m) + xi <- m$model$x + yi <- m$model$y + n <- length(yi) + yobs <- newdata[[1]] + p <- length(yobs) + if (!m$intercept) + { + varb1 <- summary(m)$coef["x","Std. Error"]^2 + xpred <- mean(yobs)/b1 + varxpred <- (varyobs + xpred^2 * varb1) / b1^2 + sdxpred <- sqrt(varxpred) + } else + { + b0 <- summary(m)$coef["(Intercept)","Estimate"] + b1 <- summary(m)$coef["xi","Estimate"] + xpred <- (mean(yobs) - b0)/b1 + sumxxbar <- sum((xi - mean(xi))^2) + if (!syobs) + { + yybar <- (mean(yobs) - mean(yi))^2 + sdxpred <- (S/b1) * (1/p + 1/n + yybar/(b1^2 * sumxxbar))^0.5 + } else + { + sdxpred <- ((varyobs^0.5/b1) + (S/b1)^2 * (1/n + ((xpred - mean(xi))^2)/sumxxbar))^0.5 + } + } + t <- qt((1 + level)/2,ntot - 2) + confxpred <- t * sdxpred + + result <- c(estimate=xpred,sdxpred=sdxpred,syobs=syobs, + confxpred=confxpred) + digits <- max(c(3,round(log10(xpred/confxpred)) + 2)) + roundedresult <- round(result,digits=digits) + confidenceinterval <- paste(roundedresult["estimate"],"+-", + roundedresult["confxpred"],xunit) + roundedresult[["confidenceinterval"]] <- confidenceinterval + invisible(roundedresult) +} +calpredict <- function(yobs,xi,yi,xunit="",level=0.95,intercept=FALSE,syobs=FALSE) +{ + if (length(xi)!=length(yi)) + { + cat("xi and yi have to be of the same length\n") + } + xi <- xi[!is.na(yi)] + yi <- yi[!is.na(yi)] + n <- length(yi) + p <- length(yobs) + if (!intercept) + { + m <- lm(yi ~ xi - 1) + } else + { + m <- lm(yi ~ xi) + } + S <- summary(m)$sigma + b1 <- summary(m)$coef["xi","Estimate"] + + if (syobs) + { + if (is.numeric(syobs)) + { + varyobs <- syobs^2 + ntot <- n + } else + { + if (length(yobs)==1) + { + cat("yobs has to contain more than one number vector, if you use syobs=TRUE\n") + } + varyobs <- var(yobs) + ntot <- n + p + } + } else + { + varyobs <- S^2 + ntot <- n + } + + if (!intercept) + { + varb1 <- summary(m)$coef["xi","Std. Error"]^2 + xpred <- mean(yobs)/b1 + varxpred <- (varyobs + xpred^2 * varb1) / b1^2 + sdxpred <- sqrt(varxpred) + } else + { + b0 <- summary(m)$coef["(Intercept)","Estimate"] + b1 <- summary(m)$coef["xi","Estimate"] + xpred <- (mean(yobs) - b0)/b1 + sumxxbar <- sum((xi - mean(xi))^2) + if (!syobs) + { + yybar <- (mean(yobs) - mean(yi))^2 + sdxpred <- (S/b1) * (1/p + 1/n + yybar/(b1^2 * sumxxbar))^0.5 + } else + { + sdxpred <- ((varyobs^0.5/b1) + (S/b1)^2 * (1/n + ((xpred - mean(xi))^2)/sumxxbar))^0.5 + } + } + t <- qt((1 + level)/2,ntot - 2) + confxpred <- t * sdxpred + + result <- c(estimate=xpred,sdxpred=sdxpred,syobs=syobs, + confxpred=confxpred) + digits <- max(c(3,round(log10(xpred/confxpred)) + 2)) + roundedresult <- round(result,digits=digits) + confidenceinterval <- paste(roundedresult["estimate"],"+-", + roundedresult["confxpred"],xunit) + roundedresult[["confidenceinterval"]] <- confidenceinterval + invisible(roundedresult) +} + +multical <- function(cf,df,intercept=FALSE) +{ + rf <- data.frame(name=levels(df$name)) + substances <- colnames(df)[-1] + for (s in substances) + { + r <- vector() + for (sample in levels(df$name)) + { + tmp <- calpredict(subset(df,name==sample)[[s]], + cf[["conc"]],cf[[s]], + intercept=intercept) + r <- c(r,tmp[["confidenceinterval"]]) + } + rf[[s]] <- r + } + return(rf) +} diff --git a/chm/00Index.html b/chm/00Index.html new file mode 100755 index 0000000..89e77ff --- /dev/null +++ b/chm/00Index.html @@ -0,0 +1,26 @@ +Calibration for analytical chemistry + + +

Calibration for analytical chemistry +

+ +
+ + + + + +

Help pages for package `chemCal' version 0.01-2

+ + + + + + + + + + + +
calplotPlot calibration graphs
calpredictEstimate measurement results including confidence intervals
din32645Calibration data from DIN 32645
pahCalibrationCalibration data for HPLC measurement of 4 PAH
+ diff --git a/chm/Rchm.css b/chm/Rchm.css new file mode 100755 index 0000000..badd579 --- /dev/null +++ b/chm/Rchm.css @@ -0,0 +1,25 @@ +BODY{ background: white; + color: black } + +A:link{ background: white; + color: blue } +A:visited{ background: white; + color: rgb(50%, 0%, 50%) } + +H1{ background: white; + color: rgb(55%, 55%, 55%); + font-family: monospace; + font-size: large; + text-align: center } + +H2{ background: white; + color: rgb(0%, 0%, 100%); + font-family: monospace; + text-align: center } + +H3{ background: white; + color: rgb(40%, 40%, 40%); + font-family: monospace } + +IMG.toplogo{ vertical-align: middle } + diff --git a/chm/calplot.html b/chm/calplot.html new file mode 100755 index 0000000..a2b8158 --- /dev/null +++ b/chm/calplot.html @@ -0,0 +1,94 @@ +Plot calibration graphs + + + + +
calplot(chemCal)R Documentation
+ + + + + +

Plot calibration graphs

+ + +

Description

+ +

+Produce graphics of calibration data, the fitted model as well +as prediction and confidence intervals. +

+ + +

Usage

+ +
+  calplot(x,y,intercept=FALSE,measurand="substance x",xunit="mg/L",yunit="Area",level=0.95)
+
+ + +

Arguments

+ + + + + + + + + + + + + + + + +
x +A vector of x values. +
y +A vector of y values. +
intercept +A boolean describing if the calibration curve is to be forced +through zero. +
measurand +The name of what is being measured as a character vector. +
xunit +The unit of the given values on the x axis as a character vector. +
yunit +The unit of the y axis as a character vector. Defaults to "Area". +
level +The confidence level of the confidence and prediction bands. Defaults to +0.95. +
+ +

Value

+ +

+A linear model object for y ~ x. You will also get a plot of the calibration +data, of your fitted model as well as lines showing the confidence limits and +the prediction limits.

+ +

Author(s)

+ +

+Johannes Ranke +jranke@uni-bremen.de +http://www.uft.uni-bremen.de/chemie/ranke +

+ + +

Examples

+ +
+data(pahCalibration)
+attach(pahCalibration)
+## Not run: calplot(conc,phenanthrene,"Phenanthrene","mg/L")
+detach(pahCalibration)
+
+ + + +
[Package Contents]
+ + diff --git a/chm/calpredict.html b/chm/calpredict.html new file mode 100755 index 0000000..dff8ec4 --- /dev/null +++ b/chm/calpredict.html @@ -0,0 +1,106 @@ +Estimate measurement results including confidence intervals + + + + +
calpredict(chemCal)R Documentation
+ + + + + +

Estimate measurement results including confidence intervals

+ + +

Description

+ +

+This function generates estimates for x values from y values, including +a confidence interval for the x values. The formulas in this function used +for prediction of concentrations from (replicate) measurements are taken from +the "Handbook of Chemometrics and Qualimetrics Part A" by D. L. Massart, +Vandeginste, B. G. M., Buydens, L. M. C., De Jong, S., Lewi, P. J. and +Smeyers-Verbeke, J, Elsevier, Amsterdam, 1997 and from the EURACHEM/CITAC +report on "Quantifying uncertainty in analytical measurement", 2000, +pp. 111f. +

+ + +

Usage

+ +
+  calpredict(yobs,xi,yi,xunit="",level=0.95,intercept=FALSE,syobs=FALSE)
+
+ + +

Arguments

+ + + + + + + + + + + + + + + + +
yobs +A numeric vector containing the observed data. +
xi +A vector of x values of the calibration. +
yi +A vector of y values of the calibration. +
xunit +The unit of the given values on the x axis as a character string. +
level +The desired confidence level for the confidence interval of the +estimates. Defaults to 0.95. +
intercept +Logical value determining if an intercept is to be fitted or not. +Default is FALSE. +
syobs +If TRUE, a standard deviation for the given y values is +calculated, and the resulting confidence interval will +include this variability (not validated yet). If FALSE (default), this +standard deviation is not included in the +confidence interval. If a numeric value is given, +it is used for the standard deviation of "real samples", +in addition to the standard deviation of the y values +in the calibration (also not validated yet). +
+ +

Value

+ +

+A list containing the estimate, its standard deviation and its +confidence interval.

+ +

Author(s)

+ +

+Johannes Ranke +jranke@uni-bremen.de +http://www.uft.uni-bremen.de/chemie/ranke +

+ + +

Examples

+ +
+data(pahCalibration)
+attach(pahCalibration)
+y <- c(51.2,51.4,51.1,51.8)
+estimate <- calpredict(y,conc,acenaphthene,xunit="mg/L")
+
+ + + +
[Package Contents]
+ + diff --git a/chm/chemCal.chm b/chm/chemCal.chm new file mode 100755 index 0000000..df88b92 Binary files /dev/null and b/chm/chemCal.chm differ diff --git a/chm/chemCal.hhp b/chm/chemCal.hhp new file mode 100755 index 0000000..3b1318b --- /dev/null +++ b/chm/chemCal.hhp @@ -0,0 +1,17 @@ +[OPTIONS] +Auto Index=Yes +Contents file=chemCal.toc +Compatibility=1.1 or later +Compiled file=chemCal.chm +Default topic=00Index.html +Display compile progress=No +Full-text search=Yes +Full text search stop list file=..\..\..\gnuwin32\help\R.stp + + +[FILES] +00Index.html +calplot.html +calpredict.html +din32645.html +pahCalibration.html diff --git a/chm/chemCal.toc b/chm/chemCal.toc new file mode 100755 index 0000000..ab7c2f1 --- /dev/null +++ b/chm/chemCal.toc @@ -0,0 +1,51 @@ + + +
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+ diff --git a/chm/din32645.html b/chm/din32645.html new file mode 100755 index 0000000..f0550f7 --- /dev/null +++ b/chm/din32645.html @@ -0,0 +1,44 @@ +Calibration data from DIN 32645 + + + + +
din32645(chemCal)R Documentation
+ + + + + +

Calibration data from DIN 32645

+ + +

Description

+ +

+Sample dataset to test the package. +

+ + +

Usage

+ +
data(pahCalibration)
+ + +

Format

+ +

+A dataframe containing 10 rows of x and y values. +

+ + +

Source

+ +

+http://www.uft.uni-bremen.de/chemie +

+ + + +
[Package Contents]
+ + diff --git a/chm/logo.jpg b/chm/logo.jpg new file mode 100755 index 0000000..b8e2149 Binary files /dev/null and b/chm/logo.jpg differ diff --git a/chm/pahCalibration.html b/chm/pahCalibration.html new file mode 100755 index 0000000..10d1774 --- /dev/null +++ b/chm/pahCalibration.html @@ -0,0 +1,48 @@ +Calibration data for HPLC measurement of 4 PAH + + + + +
pahCalibration(chemCal)R Documentation
+ + + + + +

Calibration data for HPLC measurement of 4 PAH

+ + +

Description

+ +

+This dataset was produced during a course on trace analysis +of organic contaminants. The data are far from perfect, but +good enough to serve as an example. +

+ + +

Usage

+ +
data(pahCalibration)
+ + +

Format

+ +

+A dataframe containing the areas for the four polycyclic aromatic +hydrocarbons (PAH) Acenaphthene, Phenanthrene, Anthracene and Pyrene. +Each measurement of a standard solution makes up one row. +

+ + +

Source

+ +

+http://www.uft.uni-bremen.de/chemie +

+ + + +
[Package Contents]
+ + diff --git a/data/din32645.rda b/data/din32645.rda new file mode 100644 index 0000000..4e2913a Binary files /dev/null and b/data/din32645.rda differ diff --git a/data/pahCalibration.rda b/data/pahCalibration.rda new file mode 100644 index 0000000..a0ae738 Binary files /dev/null and b/data/pahCalibration.rda differ diff --git a/data/pahMeasurements.rda b/data/pahMeasurements.rda new file mode 100644 index 0000000..657e552 Binary files /dev/null and b/data/pahMeasurements.rda differ diff --git a/man/calplot.Rd b/man/calplot.Rd new file mode 100644 index 0000000..7500912 --- /dev/null +++ b/man/calplot.Rd @@ -0,0 +1,52 @@ +\name{calplot} +\alias{calplot} +\title{Plot calibration graphs} +\description{ + Produce graphics of calibration data, the fitted model as well + as prediction and confidence intervals. +} +\usage{ + calplot(x,y,intercept=FALSE,measurand="substance x",xunit="mg/L",yunit="Area",level=0.95) +} +\arguments{ + \item{x}{ + A vector of x values. + } + \item{y}{ + A vector of y values. + } + \item{intercept}{ + A boolean describing if the calibration curve is to be forced + through zero. + } + \item{measurand}{ + The name of what is being measured as a character vector. + } + \item{xunit}{ + The unit of the given values on the x axis as a character vector. + } + \item{yunit}{ + The unit of the y axis as a character vector. Defaults to "Area". + } + \item{level}{ + The confidence level of the confidence and prediction bands. Defaults to + 0.95. + } +} +\value{ + A linear model object for y ~ x. You will also get a plot of the calibration + data, of your fitted model as well as lines showing the confidence limits and + the prediction limits. +} +\examples{ +data(pahCalibration) +attach(pahCalibration) +\dontrun{calplot(conc,phenanthrene,"Phenanthrene","mg/L")} +detach(pahCalibration) +} +\author{ + Johannes Ranke + \email{jranke@uni-bremen.de} + \url{http://www.uft.uni-bremen.de/chemie/ranke} +} +\keyword{regression} diff --git a/man/calpredict.Rd b/man/calpredict.Rd new file mode 100644 index 0000000..a91d018 --- /dev/null +++ b/man/calpredict.Rd @@ -0,0 +1,64 @@ +\name{calpredict} +\alias{calpredict} +\title{Estimate measurement results including confidence intervals} +\description{ + This function generates estimates for x values from y values, including + a confidence interval for the x values. The formulas in this function used + for prediction of concentrations from (replicate) measurements are taken from + the "Handbook of Chemometrics and Qualimetrics Part A" by D. L. Massart, + Vandeginste, B. G. M., Buydens, L. M. C., De Jong, S., Lewi, P. J. and + Smeyers-Verbeke, J, Elsevier, Amsterdam, 1997 and from the EURACHEM/CITAC + report on "Quantifying uncertainty in analytical measurement", 2000, + pp. 111f. +} +\usage{ + calpredict(yobs,xi,yi,xunit="",level=0.95,intercept=FALSE,syobs=FALSE) +} +\arguments{ + \item{yobs}{ + A numeric vector containing the observed data. + } + \item{xi}{ + A vector of x values of the calibration. + } + \item{yi}{ + A vector of y values of the calibration. + } + \item{xunit}{ + The unit of the given values on the x axis as a character string. + } + \item{level}{ + The desired confidence level for the confidence interval of the + estimates. Defaults to 0.95. + } + \item{intercept}{ + Logical value determining if an intercept is to be fitted or not. + Default is FALSE. + } + \item{syobs}{ + If TRUE, a standard deviation for the given y values is + calculated, and the resulting confidence interval will + include this variability (not validated yet). If FALSE (default), this + standard deviation is not included in the + confidence interval. If a numeric value is given, + it is used for the standard deviation of "real samples", + in addition to the standard deviation of the y values + in the calibration (also not validated yet). + } +} +\value{ + A list containing the estimate, its standard deviation and its + confidence interval. +} +\examples{ +data(pahCalibration) +attach(pahCalibration) +y <- c(51.2,51.4,51.1,51.8) +estimate <- calpredict(y,conc,acenaphthene,xunit="mg/L") +} +\author{ + Johannes Ranke + \email{jranke@uni-bremen.de} + \url{http://www.uft.uni-bremen.de/chemie/ranke} +} +\keyword{regression} diff --git a/man/din32645.Rd b/man/din32645.Rd new file mode 100644 index 0000000..901bdf0 --- /dev/null +++ b/man/din32645.Rd @@ -0,0 +1,15 @@ +\name{din32645} +\docType{data} +\alias{din32645} +\title{Calibration data from DIN 32645} +\description{ + Sample dataset to test the package. +} +\usage{data(pahCalibration)} +\format{ + A dataframe containing 10 rows of x and y values. +} +\source{ + \url{http://www.uft.uni-bremen.de/chemie} +} +\keyword{datasets} diff --git a/man/multical.Rd b/man/multical.Rd new file mode 100644 index 0000000..7d62277 --- /dev/null +++ b/man/multical.Rd @@ -0,0 +1,37 @@ +\name{multical} +\alias{multical} +\title{Calculation of results in a dataframe} +\description{ + This function provides the possibility to perform the calibration + of multiple components simultaneously, and to provide the results + including confidence intervals in a dataframe. +} +\usage{ + multical(cf,df,intercept=FALSE) +} +\arguments{ + \item{cf}{ + A data frame containig the data for the calibration standards. + } + \item{df}{ + A data frame with the measured sample data. + } + \item{intercept}{ + Logical value determining if an intercept is to be fitted or not. + Default is FALSE. + } +} +\value{ + A data frame containig the measurement results with a confidence interval. +} +\examples{ +data(pahCalibration) +data(pahMeasurements) +result <- multical(pahCalibration,pahMeasurements) +} +\author{ + Johannes Ranke + \email{jranke@uni-bremen.de} + \url{http://www.uft.uni-bremen.de/chemie/ranke} +} +\keyword{regression} diff --git a/man/pahCalibration.Rd b/man/pahCalibration.Rd new file mode 100644 index 0000000..540af4a --- /dev/null +++ b/man/pahCalibration.Rd @@ -0,0 +1,19 @@ +\name{pahCalibration} +\docType{data} +\alias{pahCalibration} +\title{Calibration data for HPLC measurement of 4 PAH} +\description{ + This dataset was produced during a course on trace analysis + of organic contaminants. The data are far from perfect, but + good enough to serve as an example. +} +\usage{data(pahCalibration)} +\format{ + A dataframe containing the areas for the four polycyclic aromatic + hydrocarbons (PAH) Acenaphthene, Phenanthrene, Anthracene and Pyrene. + Each measurement of a standard solution makes up one row. +} +\source{ + \url{http://www.uft.uni-bremen.de/chemie} +} +\keyword{datasets} diff --git a/man/pahMeasurements.Rd b/man/pahMeasurements.Rd new file mode 100644 index 0000000..77b646b --- /dev/null +++ b/man/pahMeasurements.Rd @@ -0,0 +1,19 @@ +\name{pahMeasurements} +\docType{data} +\alias{pahMeasurements} +\title{Measurement data for HPLC measurement of 4 PAH} +\description{ + This dataset was produced during a course on trace analysis + of organic contaminants. The data are far from perfect, but + good enough to serve as an example. +} +\usage{data(pahMeasurements)} +\format{ + A dataframe containing the areas for the four polycyclic aromatic + hydrocarbons (PAH) Acenaphthene, Phenanthrene, Anthracene and Pyrene + in the different samples. +} +\source{ + \url{http://www.uft.uni-bremen.de/chemie} +} +\keyword{datasets} -- cgit v1.2.1