列表和矩阵使用sapply [英] Lists and matrix using sapply
问题描述
我有一个基本的问题,并且已经在网上搜索过.我在读取文件时遇到问题.但是,我按照@Konrad的建议设法读取了文件,我对此表示赞赏:如何使R从一个大目录下的多个子目录中读取文件?
I have a perhaps basic questions and I have searched on the web. I have a problem reading files. Though, I managed to get to read my files, following @Konrad suggestions, which I appreciate: How to get R to read in files from multiple subdirectories under one large directory?
这是一个类似的问题,但是,我还没有解决.
It is a similar problem, however, I have not resolved it.
我的问题:
我在不同的文件夹中有大量具有相同名称的文件("tempo.out").此tempo.out具有5列/标题.它们都是相同的格式,有1048行和5列:
I have large number of files of with same name ("tempo.out") in different folders. This tempo.out has 5 columns/headers. And they are all the same format with 1048 lines and 5 columns:
id X Y时间温度
id X Y time temp
setwd("~/Documents/ewat")
dat.files <- list.files(path="./ress",
recursive=T,
pattern="tempo.out"
,full.names=T)
readDatFile <- function(f) {
dat.fl <- read.table(f)
}
data.filesf <- sapply(dat.files, readDatFile)
# I might not have the right sintax in sub5:
subs5 <- sapply(data.filesf,`[`,5)
matr5 <- do.call(rbind, subs5)
probs <- c(0.05,0.1,0.16,0.25,0.5,0.75,0.84,0.90,0.95,0.99)
q <- rowQuantiles(matr5, probs=probs)
print(q)
我想提取成千上万个文件的第五列(临时)并进行分位数之类的计算.
I want to extract the fifth column (temp) of each of those thousands of files and make calculations such as quantiles.
我首先尝试读取"ress"中的所有子文件
I tried first to read all subfiles in "ress"
后者没有错误,但是我的主要问题是"data.filesf"不是矩阵而是列表,实际上第5列不是我期望的.然后是以下内容:
The latter gave no error, but my main problem is the "data.filesf" is not a matrix but list, and actually the 5th column is not what I expected. Then the following:
matr5 <- do.call(rbind, subs5)
也未提供所需的值/结果.
is also not giving the required values/results.
将列变成将成为巨大矩阵的最佳方法是什么?
What could be the best way to get columns into what will become a huge matrix?
推荐答案
考虑扩展定义的函数 readDatFile ,以提取第五列 temp 并直接分配给sapply
或vapply
的矩阵(因为您预先知道所需的结构-等于nrows或1048的数字矩阵长度).然后,运行所需的rowQuantiles
:
Consider extending your defined function, readDatFile, to extract fifth column, temp, and assign directly to matrix with sapply
or vapply
(since you know ahead the needed structure -numeric matrix length equal to nrows or 1048). Then, run needed rowQuantiles
:
setwd("~/Documents/ewat")
dat.files <- list.files(path="./ress",
recursive=T,
pattern="tempo.out",
full.names=T)
readDatFile <- function(f) read.table(f)$temp # OR USE read.csv(f)[[5]]
matr5 <- sapply(dat.files, readDatFile, USE.NAMES=FALSE)
# matr5 <- vapply(dat.files, readDatFile, numeric(1048), USE.NAMES=FALSE)
probs <- c(0.05,0.1,0.16,0.25,0.5,0.75,0.84,0.90,0.95,0.99)
q <- rowQuantiles(matr5, probs=probs)
这篇关于列表和矩阵使用sapply的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!