重塑R中的数据帧

Question

我遇到了重塑大型数据帧的困难.我过去一直很幸运地避免重塑问题,这也意味着我很糟糕.

我当前的数据框看起来像这样:

unique_id    seq   response    detailed.name    treatment 
a            N1     123.23     descr. of N1     T1
a            N2     231.12     descr. of N2     T1
a            N3     231.23     descr. of N3     T1
...
b            N1     343.23     descr. of N1     T2
b            N2     281.13     descr. of N2     T2
b            N3     901.23     descr. of N3     T2
...

而且我想:

seq    detailed.name   T1           T2
N1     descr. of N1    123.23       343.23
N2     descr. of N2    231.12       281.13
N3     descr. of N3    231.23       901.23

我已经研究过reshape包,但我不确定如何将处理因子转换为单独的列名.

谢谢!

编辑:我尝试在我的本地机器(4GB双核iMac 3.06Ghz)上运行它并且它一直失败:

> d.tmp.2 <- cast(d.tmp, `SEQ_ID` + `GENE_INFO` ~ treatments)
Aggregation requires fun.aggregate: length used as default
R(5751) malloc: *** mmap(size=647168) failed (error code=12)
*** error: can't allocate region
*** set a breakpoint in malloc_error_break to debug

当我有机会的时候,我会尝试在我们更大的机器上运行它.

Answer 1

重塑对我来说似乎总是很棘手,但似乎总是有点试错.这是我最终找到的:

> x
  unique_id seq response detailed.name treatment
1         a  N1   123.23           dN1        T1
2         a  N2   231.12           dN2        T1
3         a  N3   231.23           dN3        T1
4         b  N1   343.23           dN1        T2
5         b  N2   281.13           dN2        T2
6         b  N3   901.23           dN3        T2

> x2 <- melt(x, c("seq", "detailed.name", "treatment"), "response")
> x2
  seq detailed.name treatment variable  value
1  N1           dN1        T1 response 123.23
2  N2           dN2        T1 response 231.12
3  N3           dN3        T1 response 231.23
4  N1           dN1        T2 response 343.23
5  N2           dN2        T2 response 281.13
6  N3           dN3        T2 response 901.23

> cast(x2, seq + detailed.name ~ treatment)
  seq detailed.name     T1     T2
1  N1           dN1 123.23 343.23
2  N2           dN2 231.12 281.13
3  N3           dN3 231.23 901.23

您的原始数据已经是长格式,但不是融合/强制转换使用的长格式.所以我重新融化了.第二个参数(id.vars)是不易融化的事物列表.第三个参数(measure.vars)是变化的事物列表.

然后,演员使用公式.波浪号的左侧是保持原样的东西,波浪号的右侧是用于调节值列的列.

或多或少...!

Answer 2

基于Harlan的答案 - 如果数据已经是长格式,并且在cast调用中指定了列保持值,则可以避免重熔步骤.

> x <- read.table(textConnection("  unique_id seq response detailed.name treatment
+ 1         a  N1   123.23           dN1        T1
+ 2         a  N2   231.12           dN2        T1
+ 3         a  N3   231.23           dN3        T1
+ 4         b  N1   343.23           dN1        T2
+ 5         b  N2   281.13           dN2        T2
+ 6         b  N3   901.23           dN3        T2"))
> 
> cast(x, seq + detailed.name ~ treatment, value = "response")
  seq detailed.name     T1     T2
1  N1           dN1 123.23 343.23
2  N2           dN2 231.12 281.13
3  N3           dN3 231.23 901.23