calplot. chemCal 0.1-37

Usage

calplot(object, xlim = c("auto", "auto"), ylim = c("auto", "auto"), xlab = "Concentration", ylab = "Response", alpha=0.05, varfunc = NULL)

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Arguments

object: - A univariate model object of class lm or - rlm - with model formula y ~ x or y ~ x - 1. -
xlim: - The limits of the plot on the x axis. -
ylim: - The limits of the plot on the y axis. -
xlab: - The label of the x axis. -
ylab: - The label of the y axis. -
alpha: - The error tolerance level for the confidence and prediction bands. Note that this - includes both tails of the Gaussian distribution, unlike the alpha and beta parameters - used in lod (see note below). -
varfunc: - The variance function for generating the weights in the model. - Currently, this argument is ignored (see note below). -

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Description

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Produce graphics of calibration data, the fitted model as well - as confidence, and, for unweighted regression, prediction bands.

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Value

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- A plot of the calibration data, of your fitted model as well as lines showing - the confidence limits. Prediction limits are only shown for models from - unweighted regression. -

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Note

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Prediction bands for models from weighted linear regression require weights - for the data, for which responses should be predicted. Prediction intervals - using weights e.g. from a variance function are currently not supported by - the internally used function predict.lm, therefore, - calplot does not draw prediction bands for such models.

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It is possible to compare the calplot prediction bands with the - lod values if the lod() alpha and beta parameters are - half the value of the calplot() alpha parameter.

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Examples

data(massart97ex3)
-m <- lm(y ~ x, data = massart97ex3)
-calplot(m)
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Author

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