我正在使用 R 脚本创建包含 P97、P97.5、P98、P98.5、P99、P99.5 的各种百分位数的 CDF。
我想知道是否希望将百分位数转换为独占（这类似于Excel中的PERCENTILERANK.EXC函数），我尝试将百分位数[i] / 100更改为（百分位数[i] - 0.0001）/ 100？，但看起来是一样的。
R 中是否内置了一个函数来计算这个？否则，我怎么办？我将不胜感激任何意见或建议。
# define a list of percentile values
percentiles = c(97, 97.5, 98, 98.5, 99, 99.5)
# extract unique values of grouping column
groups = unique(df[,groupingColumnName])
# loop through groups
for (gg in groups) {
# subset the data frame to include only the rows corresponding to the current group
x = df[df[groupingColumnName] == gg, analysisColumnName]
# sort the values and remove missing values
x = sort(x, decreasing = FALSE, na.last = NA)
N = length(x)
# loop through the list of percentiles and calculate the corresponding percentile values and store in a list
percentile_values = lapply(percentiles, function(p) quantile(x, p/100))
# create a new data frame containing the sorted values and corresponding cumulative probabilities and percentile values
cdfTable_g = data.frame(
group = rep(gg, N),
prob = ((1:N) - 1) / (N - 1),
value = x
)
for (i in 1:length(percentiles)){
cdfTable_g[paste0("percentile_",percentiles[i])] = percentile_values[[i]]
}
# modify the cumulative probabilities based on the current percentile values
for (i in 1:length(percentiles)){
cdfTable_g$prob[cdfTable_g$value > percentile_values[[i]]] = percentiles[i] / 100
}
# append the data frame to the master cdfTable using rbind
if (gg == groups[1]) {
cdfTable = cdfTable_g
} else {
cdfTable = rbind(cdfTable, cdfTable_g)
}
}