# calibPlane: Calculates regression plane for external standard... In transmem: Treatment of Membrane-Transport Data

## Description

A bivariated regression plane for external standard calibration is calculated to later convert signals into concentration values. It differs from `calibCurve` in the number of explanatory variables, 2 in this case. This function is useful when some interference effect is being considered such as the magnification of the interest species signal due to the presence of another (known) species in the same sample.

## Usage

 ```1 2 3``` ```calibPlane(plane, badpoint = NULL, plot = TRUE, lines = 13, theta = -30, phi = 40, xlab = "Species 1", ylab = "Species 2", zlab = "Signal", pch = 18, cex = 2) ```

## Arguments

 `plane` Data frame of numeric vectors named 'Conc', 'Conc.S' and 'Signal'. The vectors must contain the concentrations of the main species (the one whose concentration in the samples is to be known) and the secondary species (the interferent), and the standard's signals, respectively. `badpoint` Numeric vector with the points to be ignored in the regresion. This allows the easy elimination of outliers without losing the stored measurement information. `plot` Logical. If `TRUE`, the default, the calibration data is plotted. `lines` Number of lines to use in the mesh of the plane in the plot. `theta` Azimuthal angle at which the plane is visualized. `phi` Altitude angle at which the plane is visualized. `xlab` Label for X axis (main species concentration). `ylab` Label for Y axis (secondary species concentration). `zlab` Label for Z axis (response). `pch` Plotting symbols available in R. `cex` The size of pch symbols.

## Details

A linear method (i.e `lm()`) is applied to obtain the regression equation. The user must verify model assumptions such as normal distribution of residuals.

## Value

Model of the calibration plane

## Author(s)

Cristhian Paredes, craparedesca@unal.edu.co

Eduardo Rodriguez de San Miguel, erdsmg@unam.mx

## Examples

 ```1 2 3``` ``` data(planelithium) planeModel <- calibPlane(plane = planelithium) summary(planeModel\$model) ```

transmem documentation built on July 1, 2020, 10:38 p.m.