bfast01classify: Change type analysis of the bfast01 function

In bfast: Breaks For Additive Season and Trend

Description

A function to determine the change type

Usage

bfast01classify(object, alpha = 0.05, pct_stable = NULL)

Arguments

object	bfast01 object, i.e. the output of the bfast01 function.
alpha	threshold for significance tests, default 0.05
pct_stable	threshold for segment stability, unit: percent change per unit time (0-100), default NULL

Details

bfast01classify

Value

bfast01classify returns a data.frame with the following elements:

flag_type	Type of shift: (1) monotonic increase, (2) monotonic decrease, (3) monotonic increase (with positive break), (4) monotonic decrease (with negative break), (5) interruption: increase with negative break, (6) interruption: decrease with positive break, (7) reversal: increase to decrease, (8) reversal: decrease to increase
flag_significance	SIGNIFICANCE FLAG: (0) both segments significant (or no break and significant), (1) only first segment significant, (2) only 2nd segment significant, (3) both segments insignificant (or no break and not significant)
flag_pct_stable	STABILITY FLAG: (0) change in both segments is substantial (or no break and substantial), (1) only first segment substantial, (2) only 2nd segment substantial (3) both segments are stable (or no break and stable)

and also significance and percentage of both segments before and after the potentially detected break: "p_segment1", "p_segment2", "pct_segment1", "pct_segment2".

Author(s)

Rogier de Jong, Jan Verbesselt

References

de Jong R, Verbesselt J, Zeileis A, Schaepman M (2013). Shifts in global vegetation activity trends. Remote Sensing, 5, 1117–1133. http://dx.doi.org/10.3390/rs5031117

See Also

bfast01

Examples

library(zoo)
## define a regular time series
ndvi <- as.ts(zoo(som$NDVI.a, som$Time))
## fit variations
bf1 <- bfast01(ndvi)
bfast01classify(bf1, pct_stable = 0.25)

Example output

Attaching package: 'zoo'

The following objects are masked from 'package:base':

    as.Date, as.Date.numeric

  flag_type flag_significance   p_segment1 p_segment2 pct_segment1 pct_segment2
1         7                 0 1.672969e-10 0.00335625      7.83364    -2.924164
  flag_pct_stable
1               0

bfast documentation built on May 2, 2019, 6:53 p.m.