- # The Nelder-Mead simplex method
- f <- function(x, y) ((x - y) ^ 2 + (x - 2) ^ 2 + (y - 3) ^ 4) / 10
- x <- seq(0, 5, len=20)
- y <- seq(0, 5, len=20)
- z <- outer(x, y, f)
- contour(x, y, z)
- library(neldermead)
- x <- matrix(c(0, 0, 2, 0, 2, 0), 3, 2)
- polygon(x)
- for (i in 1:9) {
- cat(i,":")
- x <- neldermead(x,f)
- polygon(x)
- text(rbind(apply(x, 2, mean)), labels=i)
- }
- x
Error: unknownValueForOption: Unknown value 0 for optbase optionunknownValueForOption: Unknown value 0 for optbase optionunknownValueForOption: Unknown value 2 for optbase optionunknownValueForOption: Unknown value 0 for optbase optionunknownValueForOption: Unknown value 2 for optbase optionunknownValueForOption: Unknown value 0 for optbase option
In addition: Warning message:
In if (is(value) != "optimbase") { :
the condition has length > 1 and only the first element will be used
没有用过这种算法,不知道怎么回事,麻烦高人解释下.
这段代码来自于A First Course in Statistical Programming with R (2nd Edition)的7.3节最后一部分。
谢谢!


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