我使用loess
和loess.smooth
时遇到缺少数据的时间序列时遇到问题。
这两个命令都不适用于此玩具数据。
x <- as.Date(c(1, 2, 4, 5, 6), origin="2010-1-1")
y <- c(4, 8, 8, 28, 11)
plot(x, y, ylim=c(1,30))
lines(loess(y ~ x), col="red")
lines(loess.smooth(y=y, x=x), col="blue")
答案 0 :(得分:2)
我最终使用了以下代码:
# Data
x.1 <- as.Date(c(1, 2, 4, 5, 6), origin="2010-1-1")
x.2 <- c(1, 2, 4, 5, 6)
y <- c(4, 8, 8, 28, 11)
# x.2 - x is numeric variable
plot(x.2, y, ylim=c(1,30))
lines(loess(y ~ x.2, span=1.01), col="black", lwd=2, lty=2) # neccessary to change span default to avoid warnings (span = 0.75)
lines(loess.smooth(x.2, y, span=1.01), col = "orange", , lwd=2) # neccessary to change span default to avoid warnings (span = 2/3)
lines(smooth.spline(x.2,y), col="blue", lwd=2)
# x.1 - x is date variable
plot(x.1, y, ylim=c(1,30))
# loess() cannot deal with date variables, thus convert it to
lines(loess(y~as.numeric(x.1), span=1.01), col="red", lwd=2) # neccessary to change span default to avoid warnings (span = 0.75)
lines(loess.smooth(x.1, y, span=1.01), col = "orange", lwd=2) # neccessary to change span default to avoid warnings (span = 2/3)
lines(smooth.spline(x.1,y), col="blue", lwd=2)
问题是:
(1)loess
无法处理日期变量。
(2)必须调整span
参数(&gt; 1)。