I have a huge data frame, last 30 rows are below:
我有一个巨大的数据帧，最后30行如下:
libary(data.table)
dput(p)
dput(p)
structure(list(DATE = structure(c(1367516015, 1367516045, 1367516075,
1367516105, 1367516135, 1367516165, 1367516195, 1367516225, 1367516255,
1367516285, 1367516315, 1367516345, 1367516375, 1367516405, 1367516435,
1367516465, 1367516495, 1367516525, 1367516555, 1367516585, 1367516615,
1367516645, 1367516675, 1367516705, 1367516735, 1367516765, 1367516795,
1367516825, 1367516855, 1367516885), class = c("POSIXct", "POSIXt"
), tzone = ""), LPAR = structure(c(6L, 6L, 6L, 6L, 6L, 6L, 6L,
6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L, 6L,
6L, 6L, 6L, 6L, 6L, 6L, 6L), .Label = c("cigp01a4a004", "cigp01b4a002",
"cigp01b4a004", "cigp04a4a002", "cigp04a4a004", "cigp04b4a002",
"cigp04b4a004"), class = "factor"), ENT = c(0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5,
0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5, 0.5
), USR_SYS_CPU_PCT = c(79L, 80L, 77L, 77L, 77L, 76L, 79L, 82L,
81L, 80L, 79L, 77L, 77L, 77L, 79L, 79L, 80L, 82L, 82L, 83L, 80L,
81L, 80L, 78L, 78L, 83L, 86L, 87L, 88L, 87L), ENT_PCT = c(706.8,
693.8, 570.1, 641.5, 558.5, 601.5, 674.3, 742.3, 668.9, 722.6,
679.1, 677.2, 548.5, 644.6, 689.3, 716.1, 709.5, 767.3, 753.7,
786.4, 684.2, 735.1, 688.2, 676.6, 645.6, 788, 859.5, 832.6,
883.1, 872.2), PHYSICAL_CPU_USED = c(3.53, 3.47, 2.85, 3.21,
2.79, 3.01, 3.37, 3.71, 3.34, 3.61, 3.4, 3.39, 2.74, 3.22, 3.45,
3.58, 3.55, 3.84, 3.77, 3.93, 3.42, 3.68, 3.44, 3.38, 3.23, 3.94,
4.3, 4.16, 4.42, 4.36), PROC_QUE = c(12L, 13L, 19L, 16L, 11L,
13L, 17L, 14L, 9L, 10L, 12L, 13L, 16L, 14L, 22L, 17L, 17L, 17L,
26L, 26L, 15L, 43L, 9L, 11L, 12L, 7L, 31L, 26L, 27L, 23L), RELATIVE_CORES = c(3.53,
3.47, 2.85, 3.21, 2.79, 3.01, 3.37, 3.71, 3.34, 3.61, 3.4, 3.39,
2.74, 3.22, 3.45, 3.58, 3.55, 3.84, 3.77, 3.93, 3.42, 3.68, 3.44,
3.38, 3.23, 3.94, 4.3, 4.16, 4.42, 4.36), USED_CORES = c(2.7887,
2.776, 2.1945, 2.4717, 2.1483, 2.2876, 2.6623, 3.0422, 2.7054,
2.888, 2.686, 2.6103, 2.1098, 2.4794, 2.7255, 2.8282, 2.84, 3.1488,
3.0914, 3.2619, 2.736, 2.9808, 2.752, 2.6364, 2.5194, 3.2702,
3.698, 3.6192, 3.8896, 3.7932)), .Names = c("DATE", "LPAR", "ENT",
"USR_SYS_CPU_PCT", "ENT_PCT", "PHYSICAL_CPU_USED", "PROC_QUE",
"RELATIVE_CORES", "USED_CORES"), class = "data.frame", row.names = c(NA,
-30L))
when I like calcualate some values using data.table as below:
当我喜欢用数据计算一些值时。表如下:
p<-data.table(p)
p<-p[,RELATIVE_PERCENT:=ifelse(ENT_PCT>100, (USED_CORES/ENT)*100, USR_SYS_CPU_PCT), by= c("DATE", "LPAR")]
I get this error:
我得到这个错误:
Error in `[.data.table`(x, , `:=`(RELATIVE_PERCENT, ifelse(ENT_PCT > 100, :
Type of RHS ('integer') must match LHS ('double'). To check and coerce would
impact performance too much for the fastest cases. Either change the type of
the target column, or coerce the RHS of := yourself (e.g. by using 1L instead
of 1)
what does this error mean? How can I get around this error?
这个错误是什么意思?我怎样才能避开这个错误呢?
2 个解决方案
#1
10
The problem is that your ifelse statement returns integer type for some values and numeric (double) for some other entries. And data.table complains about the mismatch in the column type as it expects the coercion to be performed by the user (for performance reasons as given in the error). So, just wrap it around with as.numeric so that all values will be converted to double.
问题是，您的ifelse语句返回一些值的整数类型和一些其他条目的数值(double)。和数据。表抱怨列类型的不匹配，因为它期望用户执行强制执行(由于在错误中给出的性能原因)。所以，用as来包装它。数值，这样所有的值都将被转换为double。
p <- p[,RELATIVE_PERCENT := as.numeric(ifelse(ENT_PCT>100, (USED_CORES/ENT)*100,
USR_SYS_CPU_PCT)), by= c("DATE", "LPAR")]
#2
3
I did this:
我这样做:
sapply(p, class)
and noticed that one of my columns was integer. Then I did this:
注意到我的一个列是整数。然后我做了这个:
x<-x[,RELATIVE_PERCENT:=ifelse(ENT_PCT>100, ((USED_CORES/ENT)*100), as.numeric(USR_SYS_CPU_PCT)), by= c("DATE", "LPAR")]
and it is money
这就是金钱
#1
10
The problem is that your ifelse statement returns integer type for some values and numeric (double) for some other entries. And data.table complains about the mismatch in the column type as it expects the coercion to be performed by the user (for performance reasons as given in the error). So, just wrap it around with as.numeric so that all values will be converted to double.
问题是，您的ifelse语句返回一些值的整数类型和一些其他条目的数值(double)。和数据。表抱怨列类型的不匹配，因为它期望用户执行强制执行(由于在错误中给出的性能原因)。所以，用as来包装它。数值，这样所有的值都将被转换为double。
p <- p[,RELATIVE_PERCENT := as.numeric(ifelse(ENT_PCT>100, (USED_CORES/ENT)*100,
USR_SYS_CPU_PCT)), by= c("DATE", "LPAR")]
#2
3
I did this:
我这样做:
sapply(p, class)
and noticed that one of my columns was integer. Then I did this:
注意到我的一个列是整数。然后我做了这个:
x<-x[,RELATIVE_PERCENT:=ifelse(ENT_PCT>100, ((USED_CORES/ENT)*100), as.numeric(USR_SYS_CPU_PCT)), by= c("DATE", "LPAR")]
and it is money
这就是金钱