使用 R 的具有相似标题的平均列 [重复]

Question

我有一个包含 59 行和 371 列的数据框。行是我的观察/站点，列是带有时间戳作为列标题的图像。在对列标题进行排序和清理后，我剩下的是：

data<-structure(list(X20151126 = c(NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, 0.277672673867523, 0.355025896133641, NA, NA, NA), X20151126.1 = c(NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, 0.278084206794621, 0.355967923936499, 
NA, NA, NA), X20151126.2 = c(NA, NA, NA, NA, NA, NA, NA, NA, 
NA, NA, 0.277672673867523, 0.355025896133641, NA, NA, NA), X20151126.3 = c(NA, 
NA, NA, NA, NA, NA, NA, NA, NA, NA, 0.278084206794621, 0.355967923936499, 
NA, NA, NA), X20151216 = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, 
NA, 0.384717953500922, 0.476687361663067, 0.369193020073217, 
0.509256980090469, 0.695446322082805), X20151216.1 = c(0.482005639964749, 
0.477315968778509, 0.577629441578537, 0.521768662684214, 0.403182719183149, 
0.495476052715638, 0.449110279438877, 0.572210709159168, 0.639095940861963, 
0.663725301936293, 0.385697051441031, 0.476921890053818, 0.369067776922609, 
0.509928156203107, 0.696681651400943), X20160105 = c(NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, 0.414471298501795, 0.476356388531503, 
0.363677767527229, 0.536833655761341, 0.627173043983676), X20160105.1 = c(0.557391753621561, 
0.545031565171865, 0.611938234209565, 0.552637066670738, 0.462370657856108, 
0.514062089559983, 0.517862730716598, 0.607005393447421, 0.62782746269337, 
0.669313073182483, 0.415045773658901, 0.476891950837264, 0.364111066602943, 
0.535738794288108, 0.627583094107998), X20160305 = c(NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, 0.608603344509915, 0.635371377161601, 
0.609235980874035, 0.55732646087173, 0.55009492623478), X20160305.1 = c(0.663171088076713, 
0.594729693525975, 0.624064072126327, 0.60486680369263, 0.557099508853904, 
0.525207209646858, 0.597555736004227, 0.55009547536139, 0.596528841673565, 
0.609200814692677, 0.609410463440908, 0.635462899436559, 0.608558438182846, 
0.557738728019745, 0.550279584646311), X20160315 = c(NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, 0.643538550411662, 0.662874802494349, 
0.641220282780279, 0.548161668675193, 0.574401192865252), X20160315.1 = c(0.668475363330821, 
0.598489967449372, 0.627731925878224, 0.598095603148813, 0.567868324796377, 
0.310253447067502, 0.628817539418026, 0.585246425272493, 0.562730022483348, 
0.601923400619283, 0.644128383766072, 0.663057419883037, 0.640840244150391, 
0.547853260818411, 0.57379435997677), X20160315.2 = c(NA, NA, 
NA, NA, NA, NA, NA, NA, NA, NA, 0.643538550411662, 0.662874802494349, 
0.641220282780279, 0.548161668675193, 0.574401192865252), X20160315.3 = c(0.668475363330821, 
0.598489967449372, 0.627731925878224, 0.598095603148813, 0.567868324796377, 
0.310253447067502, 0.628817539418026, 0.585246425272493, 0.562730022483348, 
0.601923400619283, 0.644128383766072, 0.663057419883037, 0.640840244150391, 
0.547853260818411, 0.57379435997677), X20160325 = c(NA, NA, NA, 
NA, NA, NA, NA, NA, NA, NA, 0.617099941392511, 0.64324564948683, 
0.610466453170061, 0.524114324562118, 0.558504551047362)), row.names = c("Site_00", 
"Site_01", "Site_02", "Site_03", "Site_04", "Site_05", "Site_06", 
"Site_09", "Site_10", "Site_11", "Site_12", "Site_13", "Site_16", 
"Site_17", "Site_18"), class = "data.frame")

某些图像（但不是全部）在同一时间戳上具有多个图像，例如X20151126、X20151126.1 和 X20151126.2。但是，并非所有这些倍数都有值，正如 NA 所看到的那样。

我想创建一个新的数据框，通过计算平均值来减少这些倍数（并且它只有NA 我想保留NA）。最终，我想要这样：

x20151126<-apply(data[grep("20151126",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
x20151216<-apply(data[grep("20151216",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
x20160105<-apply(data[grep("20160105",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
x20160305<-apply(data[grep("20160305",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
x20160315<-apply(data[grep("20160315",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
x20160325<-apply(data[grep("20160325",colnames(data), value=T)],
                 MARGIN=1,FUN=mean,na.rm=TRUE)
NewData<-as.data.frame(cbind(x20151126,x20151216,x20160105,x20160305,x20160315,x20160325))

有没有一种方法可以自动执行此代码，而不必使用grep 指定所有列标题？就像我提到的，我有 371 个列标题，但并非所有列标题都有多个。另外，我有 9 个不同的表，它们看起来都与此相似。

任何建议或帮助将不胜感激。

Answer 1

您可以使用split.default 将数据拆分为类似的命名列，并使用rowMeans 计算每个列表的逐行平均值。

sapply(split.default(data, sub('\\..*', '', names(data))), rowMeans, na.rm = TRUE)

#        X20151126 X20151216 X20160105 X20160305 X20160315 X20160325
#Site_00       NaN 0.4820056 0.5573918 0.6631711 0.6684754       NaN
#Site_01       NaN 0.4773160 0.5450316 0.5947297 0.5984900       NaN
#Site_02       NaN 0.5776294 0.6119382 0.6240641 0.6277319       NaN
#Site_03       NaN 0.5217687 0.5526371 0.6048668 0.5980956       NaN
#Site_04       NaN 0.4031827 0.4623707 0.5570995 0.5678683       NaN
#Site_05       NaN 0.4954761 0.5140621 0.5252072 0.3102534       NaN
#Site_06       NaN 0.4491103 0.5178627 0.5975557 0.6288175       NaN
#Site_09       NaN 0.5722107 0.6070054 0.5500955 0.5852464       NaN
#Site_10       NaN 0.6390959 0.6278275 0.5965288 0.5627300       NaN
#Site_11       NaN 0.6637253 0.6693131 0.6092008 0.6019234       NaN
#Site_12 0.2778784 0.3852075 0.4147585 0.6090069 0.6438335 0.6170999
#Site_13 0.3554969 0.4768046 0.4766242 0.6354171 0.6629661 0.6432456
#Site_16       NaN 0.3691304 0.3638944 0.6088972 0.6410303 0.6104665
#Site_17       NaN 0.5095926 0.5362862 0.5575326 0.5480075 0.5241143
#Site_18       NaN 0.6960640 0.6273781 0.5501873 0.5740978 0.5585046

使用sub，我们只保留用于拆分数据的列名的公共部分。

sub('\\..*', '', names(data))
#[1] "X20151126" "X20151126" "X20151126" "X20151126" "X20151216" "X20151216"
#[7] "X20160105" "X20160105" "X20160305" "X20160305" "X20160315" "X20160315"
#[13] "X20160315" "X20160315" "X20160325"