R程序中的錯誤太多

Question

我剛剛在本科第二學期開始學習 R。 在這里很難弄清楚很多事情。 我希望你能指出我正確的方向嗎？

最初我不確定為什么 require 行會出錯，然后我想他們正在嘗試加載不在我的 R 安裝中的包，所以我安裝了它們。 我還發現給我的數據應該放在一個名為 auto_mpg.txt 的文件中。 但是那條線之后的錯誤對我來說很難想象。

你能幫我理解這個嗎？

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[Workspace loaded from ~/R/my_project/.RData]

> #################################################################
> #################  NIKITA TIWARI ############################
> #################################################################
> #################  DATA SUMMARY PJ1  ############################
> ##       mpg             cyl              wt           region     
> ##  Min.   : 9.00   Min.   :3.000   Min.   :1613   Min.   :1.000  
> ##  1st Qu.:17.50   1st Qu.:4.000   1st Qu.:2224   1st Qu.:1.000  
> ##  Median :23.00   Median :4.000   Median :2804   Median :1.000  
> ##  Mean   :23.51   Mean   :5.455   Mean   :2970   Mean   :1.573  
> ##  3rd Qu.:29.00   3rd Qu.:8.000   3rd Qu.:3608   3rd Qu.:2.000  
> ##  Max.   :46.60   Max.   :8.000   Max.   :5140   Max.   :3.000  
> ##                                                                
> ##             model    
> ##  ford pinto    :  6  
> ##  amc matador   :  5  
> ##  ford maverick :  5  
> ##  toyota corolla:  5  
> ##  amc gremlin   :  4  
> ##  amc hornet    :  4  
> ##  (Other)       :369
> #################################################################
> #################################################################
> 
> require(gridExtra) #given to me
Loading required package: gridExtra
Warning message:
package ‘gridExtra’ was built under R version 3.4.2 
> require(ggplot2) #given to me
Loading required package: ggplot2
Warning message:
package ‘ggplot2’ was built under R version 3.4.2 
> 
> 
> auto <- read.table("auto_mpg.txt", sep="\t", header = TRUE) #given to me
> head(auto)
            mpg.............cyl..............wt...........region
1 Min.   : 9.00   Min.   :3.000   Min.   :1613   Min.   :1.000  
2 1st Qu.:17.50   1st Qu.:4.000   1st Qu.:2224   1st Qu.:1.000  
3 Median :23.00   Median :4.000   Median :2804   Median :1.000  
4 Mean   :23.51   Mean   :5.455   Mean   :2970   Mean   :1.573  
5 3rd Qu.:29.00   3rd Qu.:8.000   3rd Qu.:3608   3rd Qu.:2.000  
6 Max.   :46.60   Max.   :8.000   Max.   :5140   Max.   :3.000  
> summary(auto) #given to me
                                     mpg.............cyl..............wt...........region
 1st Qu.:17.50   1st Qu.:4.000   1st Qu.:2224   1st Qu.:1.000  :1                        
 3rd Qu.:29.00   3rd Qu.:8.000   3rd Qu.:3608   3rd Qu.:2.000  :1                        
 Max.   :46.60   Max.   :8.000   Max.   :5140   Max.   :3.000  :1                        
 Mean   :23.51   Mean   :5.455   Mean   :2970   Mean   :1.573  :1                        
 Median :23.00   Median :4.000   Median :2804   Median :1.000  :1                        
 Min.   : 9.00   Min.   :3.000   Min.   :1613   Min.   :1.000  :1                        
> 
> 
> auto$cyl <- as.factor(auto$cyl)
Error in `$<-.data.frame`(`*tmp*`, cyl, value = integer(0)) : 
  replacement has 0 rows, data has 6
> auto$region <- as.factor(auto$region)
Error in `$<-.data.frame`(`*tmp*`, region, value = integer(0)) : 
  replacement has 0 rows, data has 6
> auto$cyl[auto$cyl == 1] <- "USA"
Error in `$<-.data.frame`(`*tmp*`, cyl, value = character(0)) : 
  replacement has 0 rows, data has 6
> auto$cyl[auto$cyl == 2] <- "EUR"
Error in `$<-.data.frame`(`*tmp*`, cyl, value = character(0)) : 
  replacement has 0 rows, data has 6
> auto$cyl[auto$cyl == 3] <- "ASIA"
Error in `$<-.data.frame`(`*tmp*`, cyl, value = character(0)) : 
  replacement has 0 rows, data has 6
> auto$region[auto$region == 1] <- "USA"
Error in `$<-.data.frame`(`*tmp*`, region, value = character(0)) : 
  replacement has 0 rows, data has 6
> auto$region[auto$region == 2] <- "EUR"
Error in `$<-.data.frame`(`*tmp*`, region, value = character(0)) : 
  replacement has 0 rows, data has 6
> auto$region[auto$region == 3] <- "ASIA"
Error in `$<-.data.frame`(`*tmp*`, region, value = character(0)) : 
  replacement has 0 rows, data has 6
> 
> auto$cyl <- factor(auto$cyl, levels=c("USA","EUR","ASIA"))
Error in `$<-.data.frame`(`*tmp*`, cyl, value = integer(0)) : 
  replacement has 0 rows, data has 6
> auto$region <- factor(auto$region, levels=c("USA","EUR","ASIA"))
Error in `$<-.data.frame`(`*tmp*`, region, value = integer(0)) : 
  replacement has 0 rows, data has 6
> summary(auto)
                                     mpg.............cyl..............wt...........region
 1st Qu.:17.50   1st Qu.:4.000   1st Qu.:2224   1st Qu.:1.000  :1                        
 3rd Qu.:29.00   3rd Qu.:8.000   3rd Qu.:3608   3rd Qu.:2.000  :1                        
 Max.   :46.60   Max.   :8.000   Max.   :5140   Max.   :3.000  :1                        
 Mean   :23.51   Mean   :5.455   Mean   :2970   Mean   :1.573  :1                        
 Median :23.00   Median :4.000   Median :2804   Median :1.000  :1                        
 Min.   : 9.00   Min.   :3.000   Min.   :1613   Min.   :1.000  :1                        
> 
> ###################################################################
> # calculate the mean mpg for cars, broken out by the number of 
> # cylinders in the car.
> ###################################################################
> 
> 
> ###################################################################
> #Provide a description of what you notice above
> ###################################################################
> # write a line describing the purpose of the next code chunk
> ###################################################################
> 
> 
> ###################################################################
> #provide a dsecriptiojn of what you notice above
> ###################################################################
> # Histograms
> ###################################################################
> # the next chunk of code is creating bar graphs and filling them 
> # with either region or cyl , with count on the y axis and 
> # mpg on the x axis
> ###################################################################
> ggplot(auto, aes(x = mpg, y = count, fill = cyl)) + geom_bar()
Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous.
Error in FUN(X[[i]], ...) : object 'count' not found
> ggplot(auto, aes(x = mpg, y = count, fill = region)) + geom_bar()
Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous.
Error in FUN(X[[i]], ...) : object 'count' not found
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # write a line describe the purpose of the next chunck of code
> ###################################################################
> b1 <- ggplot(auto, aes(x=cyl, fill=cyl)) + geom_bar()
> b2 <- ggplot(auto, aes(x=region, fill=region)) + geom_bar()
> ###################################################################
> # the above code is used to creat a specific bar graph and it's 
> # x axis is the same a the fill so that it is more clear
> ###################################################################
> # the next chunck of code is used to fill the graph with the bars
> ###################################################################
> b3 <- ggplot(auto, aes(x = cyl, fill = region)) + geom_bar(position = "fill")
> b4 <- ggplot(auto, aes(x = region, fill = cyl)) + geom_bar(position = "fill")
> grid.arrange(b1, b2 ,b3, b4, ncol= 4)
Error in FUN(X[[i]], ...) : object 'cyl' not found
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # the code below is going to make box plots of the data
> ###################################################################
> bp1 <- ggplot ( auto, aes(x = cyl, y = mpg, fill = cyl)) + geom_boxplot()
> bp2 <- ggplot ( auto, aes(x = region, y = mpg, fill = region)) + geom_boxplot()
> grid.arrange(bp1, bp2, ncol = 2)
Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous.
Error in FUN(X[[i]], ...) : object 'cyl' not found
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # the code below is going to make box plots of the data spilt into
> # 3, 4, ,5, 6, 8 data with mpg being y axis, region being x axis
> # and region being the fill
> ###################################################################
> 
> 
> 
> 
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # the code below is going to a jitter plot so basically its just a 
> # lot dots on a graph
> ###################################################################
> jp1 <- ggplot ( auto, aes(x = wt, y = mpg, fill = cyl)) + geom_jitter()
> jp2 <- ggplot ( auto, aes(x = wt, y = mpg, fill = region)) + geom_jitter()
> grid.arrange(jp1, jp2, ncol = 2)
Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous.
Error in FUN(X[[i]], ...) : object 'wt' not found
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # the code below is going to a jitter plot but separate the graphs
> # into the different regions and only that region shows up on the
> # graph 
> ###################################################################
> fg1 <- ggplot ( auto, aes(x = wt, y = mpg, fill = cyl)) + geom_jitter()
> + facet_grid(region)
Error in facet_grid(region) : object 'region' not found
> fg1
Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous.
Error in FUN(X[[i]], ...) : object 'wt' not found
> 
> 
> ###################################################################
> # provide a description of what you notice above
> ###################################################################
> # the code below is going to a jitter plot but separate the graphs
> # into the different regions and into different cyl and only that 
> # cyl and that region show up in that graph
> ###################################################################
> 

Answer 1

作為起點，錯誤消息Error in $<-.data.frame(tmp, cyl, value = integer(0)) : replacement has 0 rows, data has 6發生，因為例如auto$cyl返回NULL 。

這是因為在執行auto <- read.table("auto_mpg.txt", sep="\\t", header = TRUE)您的列名沒有按照您的代碼命名。 而不是例如cyl ，您的auto對象中的相應列似乎是cyl.............. 。 所以你應該做的第一件事是交叉檢查你的read.table函數是否按預期工作，列是否按預期命名。

此外，錯誤Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'count' not found Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'count' not found Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'count' not found表示您的auto對象中沒有名為count列（在執行summary(auto)時也未提及）。 因此，我假設您必須自己計算列count的值。

最后， Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'cyl' not found Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'cyl' not found Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'cyl' not found中的錯誤： Don't know how to automatically pick scale for object of type tbl_df/tbl/data.frame. Defaulting to continuous. Error in FUN(X[[i]], ...) : object 'cyl' not found目的是再次為您的列命名錯誤。 這也指代碼片段末尾的以下錯誤消息。

Answer 2

歡迎使用堆棧溢出！ 使用 R，您將學習一門重要的編程語言並開始使用一個有用的平台。 也許您想考慮閱讀有關如何創建最小示例並提出好問題的信息。 此外，在發布代碼時，了解您想用代碼實現什么總是有益的 - 我建議對每個重要步驟使用# comments 。

正如@rui-barradas 懷疑的那樣，我認為讀取您的數據時存在問題（這是正常情況：），盡管沒有類似的數據示例很難說。 如果它不是私有數據，您可以使用head(auto)並將結果添加到您的問題中。

但是，也許您想使用View(auto)來檢查 R 是否正確讀取您的數據集並生成所需的數據框。 （您可以通過class(auto)檢查它是否確實是 data.frame。）如果結果看起來很難看（例如列名顯示很奇怪），請使用?read.table並探索如何自定義read.table() （例如， stringsAsFactors = FALSE或sep = ";" （即 *.txt 文件數據中使用的分隔符））以控制 R 讀取數據的方式。