1 files changed, 25 insertions, 0 deletions
diff --git a/man/sigma_rl.Rd b/man/sigma_rl.Rd
new file mode 100644
index 00000000..d1c22a77
--- /dev/null
+++ b/man/sigma_rl.Rd
@@ -0,0 +1,25 @@
+\name{sigma_rl}
+\alias{sigma_rl}
+\title{ Two component error model of Rocke and Lorenzato}
+\description{
+  Function describing the standard deviation of the measurement error 
+  in dependence of the measured value:
+
+    \eqn{sigma = sqrt(sigma_low^2 + y^2 * rsd_high^2)}
+}
+\usage{
+sigma_rl(y, sigma_low, rsd_high)
+}
+\arguments{
+  \item{y}{ The magnitude of the observed value } 
+  \item{sigma_low}{ The asymptotic minimum of the standard deviation for low observed values }
+  \item{rsd_high}{ The coefficient describing the increase of the standard deviation with 
+    the magnitude of the observed value }
+}
+\value{
+  The standard deviation of the response variable.
+}
+\references{
+  Rocke, David M. und Lorenzato, Stefan (1995) A two-component model for
+  measurement error in analytical chemistry. Technometrics 37(2), 176-184.
+}