在尝试使用resphape2::dcast重塑数据时，遇到一个涉及NA条目的错误。样本数据在最后。
数据会从长到宽进行整形，但有时某些参数具有所有NA条目，这似乎是引起问题的原因。或者至少，我认为是。如果我删除了像本示例中的Ammonia这样的任何参数，该错误就会消失。
在调试dcast时，它似乎固定在这一行：
ordered <- vaggregate(.value = value, .group = overall,
.fun = fun.aggregate, ..., .default = fill, .n = n)
这会导致错误：
Error in vapply(indices, fun, .default) :
values must be type 'character',
but FUN(X[[1]]) result is type 'integer'
看到NA变量排在第一位，我认为aggregate函数可能默认为整数，即使整列都是character，但移动这些行并不能解决它。我可以找到solve it is by using na.omit的唯一方法，它将完全删除该参数。我的预期输出将尽可能保留所有NA的任何参数。第二个原因是，如果不对日期/深度进行采样，则应保留该日期/深度，并且应将这些条目设为ns（不采样）。 有没有一种方法可以解决此错误，而不必删除将要重塑的所有NA参数？
可复制的示例（数据在dcast代码下方）：
library(reshape2)
dcast(df, station + date + depth ~ parmcode, value.var = "value_qualif", fill="ns")
dcast(na.omit(df), station + date + depth ~ parmcode,
value.var = "value_qualif", fill="ns") # solves error, but removes parameter completely
示例数据：
df <- structure(list(station = c("A", "A", "A", "A", "A", "A", "A",
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A",
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A",
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A",
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A", "A",
"A", "A", "A", "A", "A", "A", "A", "A", "A", "A"), date = c("7/2/2018",
"7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018",
"7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018",
"7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018",
"7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018",
"7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/2/2018", "7/1/2018",
"7/1/2018", "7/1/2018", "7/1/2018", "7/1/2018", "7/1/2018", "7/1/2018",
"7/1/2018", "7/1/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018",
"7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018",
"7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018",
"7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018",
"7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018", "7/9/2018",
"7/9/2018", "7/9/2018"), depth = c(1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 1L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L,
18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 1L, 1L, 1L,
12L, 12L, 12L, 18L, 18L, 18L, 1L, 1L, 1L, 1L, 1L, 1L, 1L, 1L,
1L, 1L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 12L, 18L,
18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L, 18L), parmcode = c("CDOM",
"DENSITY", "DO", "ENTERO", "PH", "TOTAL", "XMS", "TEMP", "SAL",
"FECAL", "TOTAL", "FECAL", "ENTERO", "CDOM", "XMS", "TEMP", "SAL",
"PH", "DO", "DENSITY", "DO", "DENSITY", "TOTAL", "FECAL", "PH",
"CDOM", "XMS", "TEMP", "SAL", "ENTERO", "AMMONIA AS N", "AMMONIA AS N",
"AMMONIA AS N", "AMMONIA AS N", "AMMONIA AS N", "AMMONIA AS N",
"AMMONIA AS N", "AMMONIA AS N", "AMMONIA AS N", "TOTAL", "XMS",
"TEMP", "SAL", "PH", "DO", "DENSITY", "CDOM", "FECAL", "ENTERO",
"CDOM", "FECAL", "ENTERO", "PH", "DO", "TEMP", "XMS", "TOTAL",
"DENSITY", "SAL", "TOTAL", "FECAL", "ENTERO", "XMS", "TEMP",
"SAL", "PH", "DO", "DENSITY", "CDOM"), value_qualif = c(NA, NA,
NA, NA, NA, NA, NA, NA, NA, NA, "<2", "<2", "<2", "1.3", "69.67",
"16.6", "33.7", "8.1", "7.6", "24.622", "5.5", "25.279", "<2",
"<2", "7.8", "1.38", "72.96", "13.2", "33.61", "<2", NA, NA,
NA, NA, NA, NA, NA, NA, NA, "<2", "77.82", "20.8", "33.72", "8.2",
"8.8", "23.58", "1.01", "<2", "<2", "1.78", "<2", "<2", "8",
"6.5", "13.5", "67.19", "2e", "25.197", "33.58", "2e", "2e",
"<2", "75.53", "12.9", "33.61", "7.9", "5.5", "25.34", "1.77"
)), class = "data.frame", row.names = c(NA, -69L))
一些无法解答我问题的与切线相关的问题是POSIXct values become numeric in reshape2 dcast和Error with custom aggregate function for a cast() call in R reshape2
使用na.omit时，我的输出是：
station date depth CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
1 A 7/2/2018 12 1.3 24.622 7.6 <2 <2 8.1 33.7 16.6 <2 69.67
2 A 7/2/2018 18 1.38 25.279 5.5 <2 <2 7.8 33.61 13.2 <2 72.96
3 A 7/9/2018 1 1.01 23.58 8.8 <2 <2 8.2 33.72 20.8 <2 77.82
4 A 7/9/2018 12 1.78 25.197 6.5 <2 <2 8 33.58 13.5 2e 67.19
5 A 7/9/2018 18 1.77 25.34 5.5 <2 2e 7.9 33.61 12.9 2e 75.53
不使用na.omit的预期输出是：
station date depth AMMONIA CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
1 A 7/2/2018 1 ns ns ns ns ns ns ns ns ns ns ns
2 A 7/2/2018 12 ns 1.3 24.622 7.6 <2 <2 8.1 33.7 16.6 <2 69.67
3 A 7/2/2018 18 ns 1.38 25.279 5.5 <2 <2 7.8 33.61 13.2 <2 72.96
4 A 7/9/2018 1 ns 1.01 23.58 8.8 <2 <2 8.2 33.72 20.8 <2 77.82
5 A 7/9/2018 12 ns 1.78 25.197 6.5 <2 <2 8 33.58 13.5 2e 67.19
6 A 7/9/2018 18 ns 1.77 25.34 5.5 <2 2e 7.9 33.61 12.9 2e 75.53
答案 0 :(得分：1)
实际的问题是index.php?a%5Bb%5B%5D%5D=c
的三个参数（测站，日期，深度）的所有三元组（em）的所有参数都只有一个值，AMMONIA AS N具有三个NA条目
例如，
dcast(df, station + date + depth ~ parmcode, value.var = "value_qualif")
# Aggregation function missing: defaulting to length
# station date depth AMMONIA AS N CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
# 1 A 7/1/2018 1 3 0 0 0 0 0 0 0 0 0 0
# 2 A 7/1/2018 12 3 0 0 0 0 0 0 0 0 0 0
# 3 A 7/1/2018 18 3 0 0 0 0 0 0 0 0 0 0
# 4 A 7/2/2018 1 0 1 1 1 1 1 1 1 1 1 1
# 5 A 7/2/2018 12 0 1 1 1 1 1 1 1 1 1 1
# 6 A 7/2/2018 18 0 1 1 1 1 1 1 1 1 1 1
# 7 A 7/9/2018 1 0 1 1 1 1 1 1 1 1 1 1
# 8 A 7/9/2018 12 0 1 1 1 1 1 1 1 1 1 1
# 9 A 7/9/2018 18 0 1 1 1 1 1 1 1 1 1 1
一旦我们删除了重复的行，一切都会顺利进行
dcast(df[!duplicated(df), ], station + date + depth ~ parmcode, value.var = "value_qualif")
# station date depth AMMONIA AS N CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
# 1 A 7/1/2018 1 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 2 A 7/1/2018 12 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 3 A 7/1/2018 18 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 4 A 7/2/2018 1 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 5 A 7/2/2018 12 <NA> 1.3 24.622 7.6 <2 <2 8.1 33.7 16.6 <2 69.67
# 6 A 7/2/2018 18 <NA> 1.38 25.279 5.5 <2 <2 7.8 33.61 13.2 <2 72.96
# 7 A 7/9/2018 1 <NA> 1.01 23.58 8.8 <2 <2 8.2 33.72 20.8 <2 77.82
# 8 A 7/9/2018 12 <NA> 1.78 25.197 6.5 <2 <2 8 33.58 13.5 2e 67.19
# 9 A 7/9/2018 18 <NA> 1.77 25.34 5.5 <2 2e 7.9 33.61 12.9 2e 75.53
dcast(df[!duplicated(df), ], station + date + depth ~ parmcode, value.var = "value_qualif", fill = "ns")
# station date depth AMMONIA AS N CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
# 1 A 7/1/2018 1 ns ns ns ns ns ns ns ns ns ns ns
# 2 A 7/1/2018 12 ns ns ns ns ns ns ns ns ns ns ns
# 3 A 7/1/2018 18 ns ns ns ns ns ns ns ns ns ns ns
# 4 A 7/2/2018 1 ns ns ns ns ns ns ns ns ns ns ns
# 5 A 7/2/2018 12 ns 1.3 24.622 7.6 <2 <2 8.1 33.7 16.6 <2 69.67
# 6 A 7/2/2018 18 ns 1.38 25.279 5.5 <2 <2 7.8 33.61 13.2 <2 72.96
# 7 A 7/9/2018 1 ns 1.01 23.58 8.8 <2 <2 8.2 33.72 20.8 <2 77.82
# 8 A 7/9/2018 12 ns 1.78 25.197 6.5 <2 <2 8 33.58 13.5 2e 67.19
# 9 A 7/9/2018 18 ns 1.77 25.34 5.5 <2 2e 7.9 33.61 12.9 2e 75.53
或者，您可以运行
dcast(df, station + date + depth ~ parmcode, value.var = "value_qualif",
fill = NA_character_, fun.aggregate = head, n = 1)
# station date depth AMMONIA AS N CDOM DENSITY DO ENTERO FECAL PH SAL TEMP TOTAL XMS
# 1 A 7/1/2018 1 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 2 A 7/1/2018 12 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 3 A 7/1/2018 18 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 4 A 7/2/2018 1 <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA> <NA>
# 5 A 7/2/2018 12 <NA> 1.3 24.622 7.6 <2 <2 8.1 33.7 16.6 <2 69.67
# 6 A 7/2/2018 18 <NA> 1.38 25.279 5.5 <2 <2 7.8 33.61 13.2 <2 72.96
# 7 A 7/9/2018 1 <NA> 1.01 23.58 8.8 <2 <2 8.2 33.72 20.8 <2 77.82
# 8 A 7/9/2018 12 <NA> 1.78 25.197 6.5 <2 <2 8 33.58 13.5 2e 67.19
# 9 A 7/9/2018 18 <NA> 1.77 25.34 5.5 <2 2e 7.9 33.61 12.9 2e 75.53
关于NA_character_，请参见this answer。