Nav*_*MSN 5 r reshape dataframe
我正在学习 R 进行文本挖掘。我有一个 CSV 格式的电视节目时间表。节目通常从早上 06:00 开始，一直持续到第二天早上 05:00，这被称为广播日。例如：15/11/2015 的节目从早上 06:00 开始，到第二天早上 05:00 结束。
这是一个示例代码，显示了日程安排的样子：
read.table(textConnection("Sunday|\n 01-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|\nMonday|\n 02-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|"), header = F, sep = "|", stringsAsFactors = F)
其输出如下：
V1|V2
Sunday |
01-Nov-15 |
6 | Tom
some information about the program |
23.3 | Jerry
some information about the program |
5 | Avatar
some information about the program |
5.3 | Panda
some information about the program |
Monday |
02-Nov-15|
6 Jerry
some information about the program |
6.25 | Panda
some information about the program |
23.3 | Avatar
some information about the program |
7.25 | Tom
some information about the program |
我想把上面的数据转换成data.frame的形式
Date |Program|Synopsis
2015-11-1 06:00 |Tom | some information about the program
2015-11-1 23:30 |Jerry | some information about the program
2015-11-2 05:00 |Avatar | some information about the program
2015-11-2 05:30 |Panda | some information about the program
2015-11-2 06:00 |Jerry | some information about the program
2015-11-2 06:25 |Panda | some information about the program
2015-11-2 23:30 |Avatar | some information about the program
2015-11-3 07:25 |Tom | some information about the program
我很感谢任何有关我应该查看的功能或包的建议/提示。
使用data.table的替代解决方案：
library(data.table)
library(zoo)
library(splitstackshape)
txt <- textConnection("Sunday|\n 01-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|\nMonday|\n 02-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|")
tv <- readLines(txt)
DT <- data.table(tv)[, tv := gsub('[|]$', '', tv)]
wd <- levels(weekdays(1:7, abbreviate = FALSE))
DT <- DT[, temp := tv %chin% wd
][, day := tv[temp], by = 1:nrow(tvDT)
][, day := na.locf(day)
][, temp := NULL
][, idx := rleid(day)
][, date := tv[2], by = idx
][, .SD[-c(1,2)], by = idx]
DT <- cSplit(DT, sep="|", "tv", "long")[, lbl := rep(c("Time","Program","Info")), by = idx]
DT <- dcast(DT, idx + day + date + rowid(lbl) ~ lbl, value.var = "tv")[, lbl := NULL]
DT <- DT[, datetime := as.POSIXct(paste(as.character(date), sprintf("%01.2f",as.numeric(as.character(Time)))), format = "%d-%b-%y %H.%M")
][, datetime := datetime + (+(datetime < shift(datetime, fill=datetime[1]) & datetime < 6) * 24 * 60 * 60)
][, .(datetime, Program, Info)]
结果：
> DT
datetime Program Info
1: 2015-11-01 06:00:00 Tom some information about the program
2: 2015-11-01 23:30:00 Jerry some information about the program
3: 2015-11-02 05:00:00 Avatar some information about the program
4: 2015-11-02 06:00:00 Tom some information about the program
5: 2015-11-02 23:30:00 Jerry some information about the program
6: 2015-11-03 05:00:00 Avatar some information about the program
解释：
1：读取数据，转换为data.table并删除尾随|：
txt <- textConnection("Sunday|\n 01-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|\nMonday|\n 02-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|")
tv <- readLines(txt)
DT <- data.table(tv)[, tv := gsub('[|]$', '', tv)]
2：将工作日提取到新列中
wd <- levels(weekdays(1:7, abbreviate = FALSE)) # a vector with the full weekdays
DT[, temp := tv %chin% wd
][, day := tv[temp], by = 1:nrow(tvDT)
][, day := na.locf(day)
][, temp := NULL]
3：每天创建一个索引并创建一个包含日期的列
DT[, idx := rleid(day)][, date := tv[2], by = idx]
4：去除不必要的线条
DT <- DT[, .SD[-c(1,2)], by = idx]
5：将时间和节目名称分成单独的行并创建一个标签列
DT <- cSplit(DT, sep="|", "tv", "long")[, lbl := rep(c("Time","Program","Info")), by = idx]
6：使用data.table开发版中的'rowid'函数重整为宽格式
DT <- dcast(DT, idx + day + date + rowid(idx2) ~ idx2, value.var = "tv")[, idx2 := NULL]
7：创建一个日期时间列并将深夜时间设置为第二天
DT[, datetime := as.POSIXct(paste(as.character(date), sprintf("%01.2f",as.numeric(as.character(Time)))), format = "%d-%b-%y %H.%M")
][, datetime := datetime + (+(datetime < shift(datetime, fill=datetime[1]) & datetime < 6) * 24 * 60 * 60)]
8：保留需要的列
DT <- DT[, .(datetime, Program, Info)]
虽然有点乱，但似乎有效：
df <- read.table(textConnection(txt <- "Sunday|\n 01-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|\nMonday|\n 02-Nov-15|\n 6|Tom\n some information about the program|\n 23.3|Jerry\n some information about the program|\n 5|Avatar\n some information about the program|"), header = F, sep = "|", stringsAsFactors = F)
cat(txt)
Sys.setlocale("LC_TIME", "English") # if needed
weekdays <- format(seq.Date(Sys.Date(), Sys.Date()+6, 1), "%A")
days <- split(df, cumsum(df$V1 %in% weekdays))
lapply(days, function(dayDF) {
tmp <- cbind.data.frame(V1=dayDF[2, 1], do.call(rbind, split(unlist(dayDF[-c(1:2), ]), cumsum(!dayDF[-(1:2), 2]==""))), stringsAsFactors = F)
tmp[, 1] <- as.Date(tmp[, 1], "%d-%B-%y")
tmp[, 2] <- as.numeric(tmp[, 2])
tmp[, 5] <- NULL
idx <- c(FALSE, diff(tmp[, 2])<0)
tmp[idx, 1] <- tmp[idx, 1] + 1
return(tmp)
}) -> days
days <- transform(do.call(rbind.data.frame, days), V1=as.POSIXct(paste(V1, sprintf("%.2f", V11)), format="%Y-%m-%d %H.%M"), V11=NULL)
names(days) <- c("Date", "Synopsis", "Program")
rownames(days) <- NULL
days[, c(1, 3, 2)]
# Date Program Synopsis
# 1 2015-11-01 06:00:00 Tom some information about the program
# 2 2015-11-01 23:30:00 Jerry some information about the program
# 3 2015-11-02 05:00:00 Avatar some information about the program
# 4 2015-11-02 06:00:00 Tom some information about the program
# 5 2015-11-02 23:30:00 Jerry some information about the program
# 6 2015-11-03 05:00:00 Avatar some information about the program