seg.VPR {TSS.RESTREND}

Segmented Vegetation Climate Relationship

Description

For a ts with a significant breakpoints in the the VPR/VCR. This function takes annual VI max, the optimal accumulated precipitation (& temperature) before and after the breakpoint, then caculates the Standard Variance of the climate cariables.Theen an OLS is performed with a dummy variable to reperesent the breakpoint (0 before the breakpoint and 1 after it)..

Usage

seg.VPR(
  anu.VI,
  acu.RF,
  VI.index,
  breakpoint,
  rf.b4,
  rf.af,
  acu.TM = NULL,
  tm.b4 = NULL,
  tm.af = NULL,
  sig = 0.05,
  retnonsig = FALSE
)

Arguments

anu.VI

The annual (Growing season) max VI. Must be a object of class 'ts' without NA's. if anu.VI=FALSE, it will be calculated from the CTSR.VI using AnMaxVI.

acu.RF

The optimal accumulated rainfall for anu.VI. Must be a object of class 'ts' without NA's and be of equal length and temporal range to anu.VI. if anu.RF=FALSE, it will be calculated from ACP.table usingthe AnnualClim.Cal

VI.index

the index of the CTSR.VI ts that the anu.VI values occur at. Must be the same length as anu.VI. NOTE. R indexs from 1 rather than 0. if VI.index=FALSE, it will be calculated from the CTSR.VI using AnMaxVI.

breakpoint

The index of the most significant breakpoint as determined using CHOW.

rf.b4

If a breakpoint in the VPR is detected this is the optimial accumulated rainfall before the breakpoint. must be the same length as the anu.VI. If ACP.table is provided it will be generated using AnnualClim.Cal

rf.af

If a breakpoint in the VPR is detected this is the optimial accumulated rainfall after the breakpoint. must be the same length as the anu.VI. If ACP.table is provided it will be generated using AnnualClim.Cal

acu.TM

The optimal accumulated rainfall for anu.TM. Must be a object of class 'ts' without NA's and be of equal length and temporal range to anu.TM. if anu.TM=FALSE, it will be calculated from ACT.table usingthe AnnualClim.Cal

tm.b4

If a breakpoint in the VCR is detected this is the optimial accumulated temperature before the breakpoint. It must be the same length as the anu.VI. If ACT.table is provided it will be generated using AnnualClim.Cal

tm.af

If a breakpoint in the VCR is detected this is the optimial accumulated temperature after the breakpoint. It must be the same length as the anu.VI. If ACT.table is provided it will be generated using AnnualClim.Cal

sig

Significance of all the functions. defualt sig=0.05

retnonsig

Bool. New in v0.3.0. Allows TSSRESTREND to return change estimates of values that filed the sig component in the residual analysis. defualt FALSE will give the same result as eralier versions.

Value

a list of class TSSRESTREND. See TSSRESTREND for details. Note. if called seperatly from TSSRESTREND, this list will be incomplete.

Author(s)

Arden Burrell, [e-mail]

Examples

brkp <- as.integer(24) #calculated using th CHOW (DONTRUN) example
VPRres <- seg.VPR(segVPR$max.NDVI, segVPR$acum.RF, segVPR$index, brkp, segVPR$RFB4, segVPR$RFAF)
print(VPRres)