Plot EOF analysis results

Plots the rotated empirical orthogonal functions or amplitude time series resulting from eof.

eofPlot(x, type = c("coef", "amp"), rev = FALSE, ord = FALSE)

Arguments

x

result of the function eof

type

whether the EOF coefficients or amplitudes should be plotted

rev

logical indicating whether coefficients and amplitudes should be multiplied by -1

ord

logical indicating whether coefficients should be ordered by size

Value

A plot of the EOF coefficients or amplitudes.

Details

When the columns of the original data have a natural order, such as stations along a transect or months of the year, there may be no need to reorder the EOF coefficients. But if there is no natural order, such as when columns represents disparate sites around the world, the plot can be more informative if coefficients are ordered by size (ord = TRUE).

Coefficients and amplitudes for a given EOF may be more easily interpreted if rev = TRUE, because the sign of the first coefficient is arbitrarily determined and all the other signs follow from that choice.

See also

eof

Author

Alan Jassby, James Cloern

Examples

# Create an annual matrix time series
chla1 <- aggregate(sfbayChla, 1, mean, na.rm = TRUE)
chla1 <- chla1[, 1:12]  # remove stations with missing years

# eofNum (see examples) suggests n = 1
e1 <- eof(chla1, n = 1)
eofPlot(e1, type = 'coef')

eofPlot(e1, type = 'amp')