我正在尝试创建一个包含希腊符号的自定义构面标题列,用于ggplot。但是,由于某种原因,函数expression()
无法正常工作。
如果我使用
df$fac <- ifelse(df$hour==1,expression(paste(df$hour+11, " - ", df$hour, " am; ", mu, 't=', round(df$exp), sep="")), "k")
导致
> tail(df,7)
hour exp duration fac
18 1 3721141 921184.3 expression(paste(df$hour + 11, " - ", df$hour, " am; ",
19 2 2175734 921844.5 mu, "t=", round(df$exp), sep = ""), "k", "k", "k", "k",
20 24 6656036 919250.4 "k", "k")
21 6 7869344 918690.6 <NA>
22 4 2220189 920862.5 <NA>
23 5 2780161 920005.2 <NA>
24 3 2690003 922332.2 <NA>
Warning message:
In format.data.frame(x, digits = digits, na.encode = FALSE) :
corrupt data frame: columns will be truncated or padded with NAs
如果我使用
df$fac <- ifelse(df$hour==1,paste(df$hour+11, " - ", df$hour, " am; ",expression(mu), 't=', round(df$exp), sep=""), "k")
它给了我
> tail(df,7)
hour exp duration fac
18 1 3721141 921184.3 12 - 1 am; mut=3721141
19 2 2175734 921844.5 k
20 24 6656036 919250.4 k
21 6 7869344 918690.6 k
22 4 2220189 920862.5 k
23 5 2780161 920005.2 k
24 3 2690003 922332.2 k
如您所见,两种情况都没有在数据框中给我一个希腊符号。
我也使用bquote()
无济于事。名为fac
的列应该基本上存储构面标签。例如,对于第1小时,格式应为12 - 1 am; μt= 3721141
您能告诉我正确的方法吗?
以下是示例数据
> dput(df)
structure(list(hour = c(14L, 16L, 17L, 19L, 21L, 11L, 18L, 22L,
8L, 12L, 23L, 9L, 15L, 13L, 7L, 10L, 20L, 1L, 2L, 24L, 6L, 4L,
5L, 3L), exp = c(3923432.39149989, 5109851.42312691, 7070493.23531211,
20803629.8380627, 11256055.2295972, 4757385.54314779, 27576092.3667234,
9141934.32914581, 35348337.463401, 4108302.35295023, 6489550.8228499,
9848278.71615835, 3816330.82689788, 3790223.01364096, 26886283.3156086,
6308698.90957706, 17434998.9294133, 3721141.03502774, 2175733.94348253,
6656035.63316213, 7869343.75835358, 2220189.45505708, 2780160.84185653,
2690003.082563), duration = c(861081.7025, 865706.1025, 872852.945833333,
892462.086388889, 908292.911111111, 862927.383055556, 882474.983055556,
913184.621388889, 895447.985277778, 861349.923888889, 916578.3325,
878670.013611111, 862413.049722222, 861035.062777778, 911718.763055556,
868130.278333333, 901928.8125, 921184.328055556, 921844.501111111,
919250.422777778, 918690.569722222, 920862.491111111, 920005.158333333,
922332.197777778)), .Names = c("hour", "exp", "duration"), row.names = c(NA,
-24L), class = "data.frame")