美學必須是長度為 1 或與數據問題相同的長度

Question

我想用 X 值作為測量值的子集和 Y 值作為測量數據的另一個子集繪制一個圖。

在下面的示例中，我有 4 個產品 p1、p2、p3 和 p4。 每個都根據它們的偏斜、顏色和版本定價。 我想創建一個多面圖，描繪 P3 產品（Y 軸）與 P1 產品（X 軸）。

我的以下嘗試失敗了，並出現以下錯誤：

錯誤：Aesthetics 必須是長度為 1 或與 dataProblems 相同的長度：subset(price, product == "p1"), subset(price, product == "p3")

library(ggplot2)
product=c("p1","p1","p1","p1","p1","p1","p1","p1","p2","p2","p2","p2","p2","p2","p2","p2","p3","p3","p3","p3","p3","p3","p3","p3","p4","p4","p4","p4","p4","p4","p4","p4")
skew=c("b","b","b","b","a","a","a","a","b","b","b","b","a","a","a","a","b","b","b","b","a","a","a","a","b","b","b","b","a","a","a","a")
version=c(0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2,0.1,0.1,0.2,0.2)
color=c("C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2","C1","C2")
price=c(1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32)
df = data.frame(product, skew, version, color, price)
# First plot all the data
p1 <- ggplot(df, aes(x=price, y=price, colour=factor(skew))) + geom_point(size=2, shape=19)
p1 <- p1 + facet_grid(version ~ color)
p1 # This gavea very good plot. So far so good
# Now plot P3 vs P1
p1 <- ggplot(df, aes(x=subset(price, product=='p1'), y=subset(price, product=='p3'), colour=factor(skew))) + geom_point(size=2, shape=19)
p1
# failed with: Error: Aesthetics must either be length one, or the same length as the dataProblems:subset(price, product == "p1"), subset(price, product == "p3")

這是我期待的結果：

Answer 1

最好不要對aes()的變量進行子集化，而是轉換您的數據：

df1 <- unstack(df,form = price~product)
df1$skew <- rep(letters[2:1],each = 4)

p1 <- ggplot(df1, aes(x=p1, y=p3, colour=factor(skew))) + 
        geom_point(size=2, shape=19)
p1

Answer 2

問題是skew沒有在colour=factor(skew)被子集化，所以它的長度是錯誤的。 由於subset(skew, product == 'p1')與subset(skew, product == 'p3') ，在這種情況下，使用哪個子集並不重要。 因此，您可以通過以下方式解決您的問題：

p1 <- ggplot(df, aes(x=subset(price, product=='p1'),
                     y=subset(price, product=='p3'),
                     colour=factor(subset(skew, product == 'p1')))) +
              geom_point(size=2, shape=19)

請注意，大多數 R 用戶會將其寫為更簡潔：

p1 <- ggplot(df, aes(x=price[product=='p1'],
                     y=price[product=='p3'],
                     colour=factor(skew[product == 'p1']))) +
              geom_point(size=2, shape=19)

Answer 3

類似於@joran 的回答。 重塑 df 以便每個產品的價格在不同的列中：

xx <- reshape(df, idvar=c("skew","version","color"),
              v.names="price", timevar="product", direction="wide")

xx 將有列 price.p1, ... price.p4，所以：

ggp <- ggplot(xx,aes(x=price.p1, y=price.p3, color=factor(skew))) +
       geom_point(shape=19, size=5)
ggp + facet_grid(color~version)

給出圖像的結果。

Answer 4

我遇到了這個錯誤，因為我在我的 geom ( geom_text ) 中指定了一個標簽屬性，但在頂級 aes 中指定了一種顏色：

df <- read.table('match-stats.tsv', sep='\t')
library(ggplot2)

# don't do this!
ggplot(df, aes(x=V6, y=V1, color=V1)) +
  geom_text(angle=45, label=df$V1, size=2)

為了解決這個問題，我只是將標簽屬性從 geom 中移到了頂級 aes 中：

df <- read.table('match-stats.tsv', sep='\t')
library(ggplot2)

# do this!
ggplot(df, aes(x=V6, y=V1, color=V1, label=V1)) +
  geom_text(angle=45, size=2)

Answer 5

我遇到這個問題是因為數據集過濾錯誤，結果數據框為空。 甚至以下導致錯誤顯示：

ggplot(df, aes(x="", y = y, fill=grp))

因為df是空的。