R整形變得很長，使用對象作爲輸入

Question

我有一個寬格式的數據框的列表，第1列有一個因子變量，第2列又有一個年度化數據。我想要繪製這些數據。這樣做需要將它們重新塑造成長格式。這裏是一個數據幀的例子：我平時此使用reshape()

# SAMPLE DATA 
x <- structure(list(State = structure(1:3, .Label = c("Alabama", "Alaska", "Arizona", "Arkansas"), class = "factor"), Green.And.Blue.Score.2001 = c(0L, 40L, 65L), Green.And.Blue.Score.2002 = c(20L, 5L, 60L), Green.And.Blue.Score.2003 = c(35L, 15L, 30L)), .Names = c("State", "Green.And.Blue.Score.2001", "Green.And.Blue.Score.2002", "Green.And.Blue.Score.2003"), row.names = c(NA, 3L), class = "data.frame") 

x 
# State Green.And.Blue.Score.2001 Green.And.Blue.Score.2002 Green.And.Blue.Score.2003 
#1 Alabama   0       20       35 
#2 Alaska   40       5       15 
#3 Arizona   65       60       30 

。例如，這工作得很好：

# RESHAPE WIDE TO LONG (MANUALLY) 
y <- reshape(x, 
    idvar = 'State', 
    varying = c('Green.And.Blue.Score.2001', 'Green.And.Blue.Score.2002', 'Green.And.Blue.Score.2003'), 
    v.names = 'Green.And.Blue.Score.', 
    times = c('2001', '2002', '2003'), 
direction = 'long') 

y 
# State time Green.And.Blue.Score. 
# Alabama 2001  0 
# Alaska 2001  40 
# Arizona 2001  65 
# Alabama 2002  20 
# Alaska 2002  5 
# Arizona 2002  60 
# Alabama 2003  35 
# Alaska 2003  15 
# Arizona 2003  30 

但是，我不想必須手動輸入idvar，varying，v.name和times變量數十我有數據幀，並且因爲一些列名相當長且複雜，並且從數據幀到數據幀有很大差異，簡單的reshape()命令不能自動將它們解壓縮。我的想法是創建一個函數，以獲得從所述數據幀的那些輸入，該前體其如下：

# RESHAPE WIDE TO LONG (FUNCTIONALIZED) 
id <- noquote(paste("'", names(x[1]), "'", sep = "")) 
va <- noquote(paste("c('", paste(names(x)[2:length(x)], collapse = "', '"), "')", sep = "")) 
vn <- noquote(paste("'", sub("(\\..*)$", ".", names(x)[2]) , "'", sep = "")) 
ti <- noquote(paste("c('", paste(sub(".*(\\d{4})$", "\\1", names(x[2:length(x)])), collapse = "', '"), "')", sep = "")) 

每個這些匹配的從#RESHAPE WIDE TO LONG (MANUALLY)的idvar，varying，v.name，和times輸入端的輸出以上：

id 
# 'State' 
va 
# c(''Green.And.Blue.Score.2001', ''Green.And.Blue.Score.2002', ''Green.And.Blue.Score.2003') 
vn 
# ''Green.And.Blue.Score.' 
ti 
# c('2001', '2002', '2003') 

但是，當我嘗試在reshape()函數中使用這些對象，我得到一個錯誤信息：

y <- reshape(x, 
    idvar = id, 
    varying = va, 
    v.names = vn, 
    times = ti, 
direction = 'long') 

Error in [.data.frame(data, , varying[[i]][1L]) : undefined columns selected

我敢肯定我的'functionalize'reshape()的解決方案並不理想。我應該做些什麼呢？

Answer 1

爲從名稱中提取的材料加上引號會導致錯誤。這是該代碼的簡化。請注意，我刪除了v.names和次數，因爲當列名由「。」正確分隔時，它們是自動計算的。

y <- reshape(x, 
    idvar = names(x)[1], 
    varying = names(x)[-1], 

direction = 'long') 
y 
#-----  
      State time Score 
Alabama.2001 Alabama 2001  0 
Alaska.2001 Alaska 2001 40 
Arizona.2001 Arizona 2001 65 
Alabama.2002 Alabama 2002 20 
Alaska.2002 Alaska 2002  5 
Arizona.2002 Arizona 2002 60 
Alabama.2003 Alabama 2003 35 
Alaska.2003 Alaska 2003 15 
Arizona.2003 Arizona 2003 30 

如果我們用這條新的例子中，我們可以在該給出一個合理的結果，「.S」獲得了「分裂」。第一階段和「拆分」模式之間的塔名的文本被移動到列名，而導致狀態名稱和年獲得appeanded一起作爲一個rowname：

y <- reshape(x, 
     idvar = names(x)[1], 
    varying = names(x)[-1], 
    split = list(regexp = "\\.S", include = TRUE), 
    direction = 'long') 
    y 

        State  time Green.And.Blue. 
Alabama.Score.2001 Alabama Score.2001    0 
Alaska.Score.2001 Alaska Score.2001    40 
Arizona.Score.2001 Arizona Score.2001    65 
Alabama.Score.2002 Alabama Score.2002    20 
Alaska.Score.2002 Alaska Score.2002    5 
Arizona.Score.2002 Arizona Score.2002    60 
Alabama.Score.2003 Alabama Score.2003    35 
Alaska.Score.2003 Alaska Score.2003    15 
Arizona.Score.2003 Arizona Score.2003    30