我正试图在绘制数据集之前构建数据集.我决定使用function factory gammaplot.ff()
,我的代码的第一个版本如下:
PowerUtility1d <- function(x, delta = 4) {
return(((x+1)^(1 - delta)) / (1 - delta))
}
PowerUtility1d <- Vectorize(PowerUtility1d, "x")
# function factory allows multiparametrization of PowerUtility1d()
gammaplot.ff <- function(type, gamma) {
ff <- switch(type,
original = function(x) PowerUtility1d(x/10, gamma),
pnorm_wrong = function(x) PowerUtility1d(2*pnorm(x)-1, gamma),
pnorm_right = function(x) PowerUtility1d(2*pnorm(x/3)-1, gamma)
)
ff
}
gammaplot.df <- data.frame(type=numeric(), gamma=numeric(),
x=numeric(), y=numeric())
gammaplot.gamma <- c(1.1, 1.3, 1.5, 2:7)
gammaplot.pts <- (-1e4:1e4)/1e3
# building the data set
for (gm in gammaplot.gamma) {
for (tp in c("original", "pnorm_wrong", "pnorm_right")) {
fpts <- gammaplot.ff(tp, gm)(gammaplot.pts)
dataChunk <- cbind(tp, gm, gammaplot.pts, fpts)
colnames(dataChunk) <- names(gammaplot.df)
gammaplot.df <- rbind(gammaplot.df, dataChunk)
}
}
# rbind()/cbind() cast all data to character, but x and y are numeric
gammaplot.df$x <- as.numeric(as.character(gammaplot.df$x))
gammaplot.df$y <- as.numeric(as.character(gammaplot.df$y))
事实证明,整个数据帧都包含字符数据,所以我必须手动将其转换回来(我花了一段时间才发现!).所以搜索indicates,这是因为type变量是字符.为了避免这种情况(您可以想象在构建数据集时角色数据的性能问题!)我对代码做了一些修改:
gammaplot.ff <- function(type, gamma) {
ff <- switch(type,
function(x) PowerUtility1d(x/10, gamma),
function(x) PowerUtility1d(2*pnorm(x)-1, gamma),
function(x) PowerUtility1d(2*pnorm(x/3)-1, gamma)
)
ff
}
for (gm in gammaplot.gamma) {
for (tp in 1:3) {
fpts <- gammaplot.ff(tp, gm)(gammaplot.pts)
dataChunk <- cbind(tp, gm, gammaplot.pts, fpts)
colnames(dataChunk) <- names(gammaplot.df)
gammaplot.df <- rbind(gammaplot.df, dataChunk)
}
}
这对我来说很好,但我丢失了一个不言自明的字符参数,这是一个缺点.有没有办法在不将所有数据隐式转换为字符的情况下保留function factory的第一个版本?
如果有其他方法可以达到同样的效果,我很乐意try 一下.