IDPmisc (version 0.9.3)

ilagplot: 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, border = FALSE,
         main = NULL, cex.main = 2 * par("cex.main"), ...)

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 i

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

border

Shall border be drawn between the colors in the legend: TRUE / FALSE

main

Title

cex.main

Character size of title

...

Additional arguments to plot.default

Value

• Maximum number of counts per Pixel found.

concept

• large dataset
• huge dataset

Details

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

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)*10})

  ## 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)*10})

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