R 变异以计算多个列的平均值，而无需将其打印出来

我希望采用包含NA个值的54列的行平均数，而不必拼写每一列，即，我希望使用:来 Select 我要使用的列:

data1 <- data %>%
  rowwise() %>%
  mutate(m = mean(c(A1:C3), na.rm=T))

然而，当我这样做时，我得到以下错误:

Error in `mutate()`:
i In argument: `m = mean(c(A1:C3), na.rm = T)`.
i In row 2.
Caused by error in `A1:C3`:
! NA/NaN argument

显然，na.rm = T的论点没有被考虑在内？如果我拼写出所有列，即，

data1 <- data %>%
  rowwise() %>%
  mutate(m = mean(c(A1, B1, C1, D1, ...), na.rm=T))

但这非常乏味，如果没有必要，我不想写出54个列名.你有什么办法在tidyverse人的世界里做到这一点吗？下面是它的重述:

data <- structure(list(SampleID = c(5, 6), StationID = c("ROC", "DAK"
), Date = structure(c(1127361600, 1347336000), class = c("POSIXct", 
"POSIXt"), tzone = ""), A1 = c(100, 50), B1 = c(100, 10), C1 = c(100, 
30), D1 = c(100, 10), E1 = c(100, 0), F1 = c(60, 20), G1 = c(60, 
100), H1 = c(0, 10), I1 = c(40, 10), J1 = c(40, 10), K1 = c(100, 
30), L1 = c(40, 20), M1 = c(40, 10), N1 = c(40, 10), O1 = c(100, 
100), P1 = c(100, 0), Q1 = c(80, 10), R1 = c(100, NA), S1 = c(60, 
10), T1 = c(100, 100), U1 = c(70, 10), V1 = c(70, 10), W1 = c(100, 
100), X1 = c(100, 30), Y1 = c(80, 30), Z1 = c(30, 10), A2 = c(20, 
20), B2 = c(60, 100), C2 = c(30, 50), D2 = c(100, 10), E2 = c(20, 
0), F2 = c(30, 0), G2 = c(20, 30), H2 = c(30, 30), I2 = c(100, 
60), J2 = c(0, 10), K2 = c(20, 100), L2 = c(100, 40), M2 = c(100, 
40), N2 = c(100, 100), O2 = c(50, NA), P2 = c(20, NA), Q2 = c(40, 
NA), R2 = c(40, NA), S2 = c(100, NA), T2 = c(30, NA), U2 = c(30, 
NA), V2 = c(100, NA), W2 = c(100, NA), X2 = c(100, NA), Y2 = c(100, 
NA), Z2 = c(50, NA), A3 = c(50, NA), B3 = c(50, NA), C3 = c(100, 
NA)), row.names = 5:6, class = "data.frame")

还要注意，这里的列名是我用c(paste0(LETTERS[1:26], "1"), paste0(LETTERS[1:26], "2"), paste0(LETTERS[1:3], "3")发明的列名，它们不是我的og数据的列名.