ilagplot {IDPmisc}R Documentation

Image Lag Plot Matrix for Large Time Series

Description

Produces an image lag plot matrix of large timeseries where the colors encode the density of the points in the lag plots.

Usage

ilagplot(x, set.lags = 1,
         pixs = 1, zmax = NULL, ztransf = function(x){x},
         colramp = IDPcolorRamp, mfrow=NULL,
         main = NULL, d.main = 1, cex.main = 2*par("cex.main"),
         legend = TRUE, d.legend = 1,
         cex.axis = par("cex.axis"), las = 1,
         border=FALSE, mar = c(3,3,2,0), oma = c(3,3,1,0), ...)

Arguments

x ts object or ordinary vector
set.lags vector of lags to be displayed
pixs Pixel size in mm
zmax Maximum counts per Pixel to be plotted. When NULL each lag plot has its individual scale. If a number >= maximum number of counts per pixel is supplied, the scale will be identical for all lag plots. The maximum of the number per pixel is delivered by the return value. Beware: zmax has its meaning only for ilagplots with identical settings for main, legend, mar and oma!
ztransf Function to transform the counts. The user has to make sure that the transformed counts lie in the range [0,zmax], where zmax is any positive number (>=2).
colramp Color ramp to encode the density of the points within a pixel
mfrow See Argument mfrow in par
main Title
d.main Vertical distance between upper border of scatter plots and the title line in multiples of title height.
cex.main Magnification used for title relative to the current setting of cex.
legend Logical. When FALSE, no legend is plotted and space is saved in figure region.
d.legend Horizontal distance between right border of scatter plots and legend in multiples of title height.
cex.axis Magnification used for axis annotation relative to the current setting of cex.
las Orientation of labels on axes.
border Logical. When TRUE, a border is drawn around the individual colors in the legend.
mar, oma Margin and outer margin respectively. Cf. par
... Additional arguments to par

Details

Code is based on R function lag.plot V1.7.

Value

Maximum number of counts per Pixel found.

Note

When you get the error message "Zmax too small! Densiest aereas are out of range!" you must run the function with identical parameters but without specifying zmax. The value returned gives you the minimum value allowed for zmax.

Author(s)

Andreas Ruckstuhl, refined by Rene Locher

See Also

ipairs, ixyplot, Image

Examples

if(require(SwissAir)) {
  data(AirQual)

  ## low correlation
  ilagplot(AirQual[,c("ad.O3")],set.lags = 1:9,
         ztransf=function(x){x[x<1] <- 1; log2(x)})

  ## high correlation
  Ox <- AirQual[,c("ad.O3","lu.O3","sz.O3")]+
    AirQual[,c("ad.NOx","lu.NOx","sz.NOx")]-
      AirQual[,c("ad.NO","lu.NO","sz.NO")]
  names(Ox) <- c("ad","lu","sz")
  ilagplot(Ox$ad,set.lags = 1:9,
           ztransf=function(x){x[x<1] <- 1; log2(x)})

  ## cf. ?AirQual for the explanation of the physical
  ## and chemical background
} else print("Package SwissAir is not available")

[Package IDPmisc version 1.0.01 Index]