R: Plot a Model-data Comparison Diagram

plotTaylor {oce} | R Documentation

## Plot a Model-data Comparison Diagram

### Description

Creates a diagram as described by Taylor (2001). The graph is in the form of a semicircle, with radial lines and spokes connecting at a focus point on the flat (lower) edge. The radius of a point on the graph indicates the standard deviation of the corresponding quantity, i.e. x and the columns in y. The angle connecting a point on the graph to the focus provides an indication of correlation coefficient with respect to x. The “east” side of the graph indicates R=1, while R=0 is at the “north edge” and R=-1 is at the “west” side. The `x` data are indicated with a bullet on the graph, appearing on the lower edge to the right of the focus at a distance indicating the standard deviation of `x`. The other points on the graph represent the columns of `y`, coded automatically or with the supplied values of `pch` and `col`. The example shows two tidal models of the Halifax sealevel data, computed with `tidem` with just the M2 component and the S2 component; the graph indicates that the M2 model is much better than the S2 model.

### Usage

    plotTaylor(x, y, scale, pch, col, labels, pos, ...)

### Arguments

`x` | a vector of reference values of some quantity, e.g. measured over time or space.
`y` | a matrix whose columns hold values of values to be compared with those in x. (If `y` is a vector, it is converted first to a one-column matrix).
`scale` | optional scale, interpreted as the maximum value of standard deviation.
`pch` | list of characters to plot, one for each column of `y`.
`col` | list of colors for points on the plot, one for each column of `y`.
`labels` | optional vector of strings to use for labelling the points.
`pos` | optional vector of positions for labelling strings. If not provided, labels will be to the left of the symbols.
`...` | optional arguments passed by `plotTaylor` to more child functions.

### Author(s)

Dan Kelley

### References

Taylor, Karl E., 2001. Summarizing multiple aspects of model performance in a single diagram, J. Geophys. Res., 106:D7, 7183–7192.

### Examples

    library(oce)
    data(sealevel)
    x <- sealevel[["elevation"]]
    M2 <- predict(tidem(sealevel, constituents="M2"))
    S2 <- predict(tidem(sealevel, constituents=c("S2")))
    plotTaylor(x, cbind(M2, S2))

[Package oce version 1.1-1 Index]