features {qualV} | R Documentation |
Qualitative Features of Time Series
Description
A time series is characterised by a sequence of characters,
indicating features of the time series itself, of its first or second
derivative, steepness or level of values.
Usage
f.slope(x, y, f = 0.1)
f.curve(x, y, f = 0.1)
f.steep(x, y, f1 = 1, f2 = 0.1)
f.level(y, high = 0.8, low = 0.2)
Arguments
x |
vector of time |
y |
input y values |
f |
factor defining the limit for constant (f.slope ) or linear (f.curve ) sequences |
f1 |
factor for the upper bound of steepness |
f2 |
factor for the lower bound of steepness |
high |
lower limit of high values |
low |
upper limit of low values |
Details
For the first derivative the segment between two values is
characterised by increasing ('A'), decreasing ('B') or constant ('C') and for
the second by convex ('K'), concave ('I') or linear ('J'). For the property of
the first derivative the segment between two values is characterised
by very steep ('S'), steep ('T') or not steep ('U') or the values are divided
into high ('H'), low ('L') or values in between ('M'). For
the last two cases the values will be standardised to ignore quantitative
deviations.
Value
See Also
LCS
, qvalLCS
Examples
data(phyto)
bbobs <- dpill(obs$t, obs$y)
n <- tail(obs$t, n = 1) - obs$t[1] + 1
obsdpill <- ksmooth(obs$t, obs$y, kernel = "normal", bandwidth = bbobs,
n.points = n)
obss <- data.frame(t = obsdpill$x, y = obsdpill$y)
obss <- obss[match(sim$t, obss$t), ]
f.slope(obss$t, obss$y)
f.curve(obss$t, obss$y)
f.steep(obss$t, obss$y, f1 = 30, f2 = 10)
f.level(obss$y)
[Package
qualV version 0.2-3
Index]