wq (version 0.2-9)

plotTsTile: Image plot of monthly time series

Description

Monthly values are transformed into deciles or other bins, and corresponding colors are plotted in a month by year matrix.

Usage

plotTsTile(x, title = NULL, trim = TRUE, four = TRUE, loganom = TRUE)

Value

An image plot of monthly values classified into either deciles or into four bins as described above (and corresponding object of class trellis).

Rdversion

1.1

Details

If four = TRUE, then x is first divided into a positive and negative bin. Each bin is then further divided into two bins by its mean, yielding a total of four bins. If four=FALSE, then x is simply divided into deciles. In either case, each bin has its own assigned color, with colors ranging from dark blue (smallest numbers) through light blue and pink to red.

Although four = TRUE can be useful for any data in which 0 represents a value with special significance, it is especially so for data converted into log-anomalies, i.e., log10(x)/mean(x, na.rm=TRUE). The mean month then has value 0, and a value of -1, for example, indicates original data equal to one-tenth the mean. Log-anomaly transforms can be particularly appropriate for biological populations, in which variability is often approximately proportional to the mean.

References

O'Brien T., Lopez-Urrutia A., Wiebe P.H., Hay S. (editors) (2008) ICES Zooplankton Status Report 2006/2007. ICES Cooperative Research Report 292, International Council for the Exploration of the Sea, Copenhagen, 168 p.

Examples

# plot log-anomalies in four bins
chl27 = sfbayChla[, 's27']
plotTsTile(chl27, 
  title = 'SF Bay station 27<nlog>-anomalies of chlorophyll')

# plot deciles
plotTsTile(chl27, title = 'SF Bay station 27<n>chlorophyll', 
  four = FALSE, loganom = FALSE)</n>

<keyword>hplot</keyword>
<keyword>ts</keyword></nlog>