如何将多行组合成R中的一个观察结果 [英] How to combine multiple rows into one observation in R
问题描述
我有一个数据框架,其中一列V4)包含字符串和数字。我想通过V2和V1中给出的分组来分割V4,并将结果作为三个单独的列附加到数据框中。
编辑:作为我的原始示例数据框没有很好地捕捉问题的复杂性,这里是一个更准确的例子:
> df< - data.frame (V1 = c(rep(SN,8),rep(JK,4)),
V2 = c(1,1,2,2,3,3,3,1, 1,2),
V3 = c(图片,响应,声音,声音,响应,声音,声音 ,响应,声音,声音),
V4 = c(照片,100,XYZc02i03,XYZq02i03,200,ZYXc01i30,ZYXq01i30 XYZc02i40,200,XYZc02i03,XYZq02i03),
stringsAsFactors = FALSE)
> V1 V2 V3 V4
SN 1 Picture Photo
SN 1响应100
SN 2声音XYZc02i03
SN 2声音XYZq02i03
SN 2响应200
SN 3声音ZYXc01i30
SN 3声音ZYX q01i30
SN 3响应100
JK 1声音XYZc02i40
JK 1响应200
JK 2声音XYZc02i03
JK 2声音XYZq02i03
我想得到这样的东西:
V1 V2 V3 V4 V5 V6
SN 1图片照片NA 100
SN 2声音XYZc02i03 XYZq02i03 200
SN 3声音ZYXc01i30 ZYXq01i30 100
JK 1声音XYZc02i40 NA 200
JK 2声音XYZc02i03 XYZq02i03 NA
编辑:我并不总是有相同数量在V2中观察,这意味着在我想要获得的数据帧中可能会出现V4,V5或V6的缺失值。
编辑2:V6应映射到响应V3,V4和V5中的变量理想地以连续的顺序从V3映射声音值。
我将非常感谢任何关于这方面的建议。或者,如果这个问题已经解决了,我错过了,链接也是很棒的。
你不在 df
的定义中需要一个 cbind
。你会使用这样的东西:
df< - data.frame(V1 = rep(SN,6) ,
/ pre>
V2 = rep(2:3,each = 3),
V3 = c(声音,声音,响应,声音,声音 ,
V4 = c(XYZc02i03,XYZq02i03,200,ZYXc01i30,ZYXq01i30,100),
stringsAsFactors = FALSE)
但是给出一个像你所描述的数据框,你可以通过以下方式获得所需的结果:
max.subset.len< - 3#或者可能最大(sapply(split(df,list(df $ V1,df $ V2)),FUN = nrow))
fun< - function(v4){length(v4)< - max.subset.len; v4}
agg< - 聚合(df $ V4,by = list(df $ V1,df $ V2),FUN = fun)
结果< - cbind(agg [1:2] agg [[3]])
I am relatively new to R and I am kind of hung up at trying to put my data into a suitable format. It seems like the reshape package might be useful for this, but I don't get any further than that.
I have a data frame in which one of the columns (V4) contains strings and numericals. I would like to split V4 by the grouping given in V2 and V1 and attach the results as three seperate columns to the data frame.
Edit: As my original example data frame did not quite capture the complexity of the problem, here is a more accurate example:
>df <- data.frame(V1=c(rep("SN", 8),rep("JK", 4)), V2=c(1,1,2,2,2,3,3,3,1,1,2,2), V3=c("Picture", "Response", "Sound", "Sound", "Response", "Sound", "Sound", "Response", "Sound", "Response", "Sound", "Sound"), V4=c("Photo", "100", "XYZc02i03", "XYZq02i03", 200, "ZYXc01i30", "ZYXq01i30", 100, "XYZc02i40", 200, "XYZc02i03", "XYZq02i03" ), stringsAsFactors=FALSE) >V1 V2 V3 V4 SN 1 Picture Photo SN 1 Response 100 SN 2 Sound XYZc02i03 SN 2 Sound XYZq02i03 SN 2 Response 200 SN 3 Sound ZYXc01i30 SN 3 Sound ZYXq01i30 SN 3 Response 100 JK 1 Sound XYZc02i40 JK 1 Response 200 JK 2 Sound XYZc02i03 JK 2 Sound XYZq02i03
And I want to get something like this:
V1 V2 V3 V4 V5 V6 SN 1 Picture Photo NA 100 SN 2 Sound XYZc02i03 XYZq02i03 200 SN 3 Sound ZYXc01i30 ZYXq01i30 100 JK 1 Sound XYZc02i40 NA 200 JK 2 Sound XYZc02i03 XYZq02i03 NA
EDIT: I don't always have the same number of observations in V2, which means there could be missing values for V4, V5, or V6 in the data frame I want to get.
Edit2: V6 should map onto the "response" Variable from V3, V4 and V5 ideally map on the "Sound" values from V3 in consecutive order.
I would be very appreciative of any advice on how to go about this. Or, if this problem has been solved elswhere and I missed it, a link would also be great.
解决方案You don't need a
cbind
in your definition ofdf
. You'd use something like this:df <- data.frame(V1=rep("SN", 6), V2=rep(2:3, each=3), V3=c("Sound", "Sound", "Response", "Sound", "Sound", "Response"), V4=c("XYZc02i03", "XYZq02i03", 200, "ZYXc01i30", "ZYXq01i30", 100), stringsAsFactors=FALSE)
But given a dataframe like the one you describe, you can get the desired results with:
max.subset.len <- 3 # or maybe max(sapply(split(df, list(df$V1, df$V2)), FUN=nrow)) fun <- function(v4) {length(v4) <- max.subset.len; v4} agg <- aggregate(df$V4, by=list(df$V1, df$V2), FUN=fun) results <- cbind(agg[1:2], agg[[3]])
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