Question

使用DV和FF作为长度为47的向量：

analyse <- function(DV,FF)
{
correct <- rep(0,47)
matrix <- array(rep(0,47*3), dim=c(47,3))

for(i in 1:47)
{
if(DV[i] > 50) {if(FF[i] > 50) {correct[i] <- i}
}
else
{
if(FF[i] < 0){correct[i] <- i}}
}

for(i in 1:47)
{
if((correct[i] == 0) == FALSE)
{
matrix[i,1] <- DV[i]
matrix[i,2] <- FF[i]
matrix[i,3] <- matrix[i,1] - matrix[i,2]
}
}

for(i in 47:1)
{
if(matrix[i,1]==0) {matrix<-matrix[-i]
}
}
return(matrix)
}

我不明白为什么会收到此错误：

矩阵[i，1]中的错误：维数不正确

提前致谢

[edit]样本数据：

DV <- c(56.2, 59.2, 50.9, 46.9, 50.7, 47.3, 53.6, 57.8, 42.7, 45.0, 47.3, 44.1, 51.5, 50.0, 50.3, 50.4, 51.7, 47.8, 46.8, 40.0, 45.5, 57.4, 51.6, 36.1, 34.8, 41.2, 59.1, 62.5, 55.0, 53.8, 52.4, 44.5, 42.2, 50.1, 61.3, 49.6, 38.2, 51.1, 44.7, 40.8, 46.1, 53.5, 54.7, 50.3, 48.8, 53.7, 52.0)

DF <- c(49.95662, 51.93295, 53.02263, 50.00784, 48.55493, 49.93520, 48.70022, 50.98856, 52.51411, 47.02938, 47.86480, 48.70022, 47.53790, 50.22578, 49.68094, 49.78991, 49.82623, 50.29842, 48.88184, 48.51861, 46.04866, 48.04641, 52.36882, 50.26210, 44.63208, 44.15988, 46.48454, 52.98631, 54.22128, 51.49707, 51.06120, 50.55268, 47.68319, 46.84776, 49.71726, 53.78541, 49.53565, 45.39485, 50.08049, 47.75583, 46.33925, 48.26435, 50.95223, 51.38811, 49.78991, 49.24506, 51.02488)


[edit] result:

Scope of the function it to obtain a matrix which contains:
- every couple of DV[i] and FF[i] which are not both higher (or lower) than 50.
- their difference as third column.


example:

DV[1] = 55
FF[1] = 45

DV > 50 and FF < 50, so I report them in the matrix:

DV[1] -> matrix [1,1]
FF[1] -> matrix[1,2]

第三栏是他们的不同之处：

matrix[1,3] <- matrix[1,1] - matrix[1,2].

当DV [2] = 55且FF [2] = 55时，analyze（）不执行任何操作，因为它们都高于50。

Answer 1

您可以使用矢量化解决方案替换最终的for循环：

analyse <- function(DV,FF)
{
  correct <- rep(0,47)
  matrix <- array(rep(0,47*3),dim=c(47,3))

  for(i in 1:47)
  {
    if( DV[i] > 50 ) { 
      if( FF[i] > 50) {
        correct[i] <- i 
      } 
    }

    else {
      if( FF[i] < 0) {
        correct[i] <- i}
    }
  }

  for(i in 1:47)
  {
    if( (correct[i] == 0) == FALSE)
    {
      matrix[i,1] <- DV[i]
      matrix[i,2] <- FF[i]
      matrix[i,3] <- matrix[i,1] - matrix[i,2]
    }
  }

  matrix <- matrix[ matrix[,1] != 0, ]

  return(matrix)
}

analyse(DV, FF)
#      [,1]     [,2]     [,3]
# [1,] 59.2 51.93295  7.26705
# [2,] 50.9 53.02263 -2.12263
# [3,] 57.8 50.98856  6.81144
# [4,] 51.6 52.36882 -0.76882
# [5,] 62.5 52.98631  9.51369
# [6,] 55.0 54.22128  0.77872
# [7,] 53.8 51.49707  2.30293
# [8,] 52.4 51.06120  1.33880
# [9,] 54.7 50.95223  3.74777
# [10,] 50.3 51.38811 -1.08811
# [11,] 52.0 51.02488  0.97512

但正如你所提到的，这是低效的。不需要循环。以下功能提供相同的输出。

analyse2 <- function(DV, FF) {
  indx <- (DV > 50 & FF > 50) | FF < 0
  dif <- DV[indx] - FF[indx]
  matrix(c(DV[indx], FF[indx], dif), ncol=3)
}
analyse2(DV, FF)
#      [,1]     [,2]     [,3]
# [1,] 59.2 51.93295  7.26705
# [2,] 50.9 53.02263 -2.12263
# [3,] 57.8 50.98856  6.81144
# [4,] 51.6 52.36882 -0.76882
# [5,] 62.5 52.98631  9.51369
# [6,] 55.0 54.22128  0.77872
# [7,] 53.8 51.49707  2.30293
# [8,] 52.4 51.06120  1.33880
# [9,] 54.7 50.95223  3.74777
# [10,] 50.3 51.38811 -1.08811
# [11,] 52.0 51.02488  0.97512

all.equal(analyse(DV, FF), analyse2(DV, FF))
[1] TRUE

修改

根据您的描述，您希望将小于50的值报告给矩阵，而不是原始函数中的大于50的值。这是一个编辑过的函数，在第二行添加了感叹号。

analyse2 <- function(DV, FF) { indx <- (!DV > 50 & FF > 50) | FF < 0 dif <- DV[indx] - FF[indx] matrix(c(DV[indx], FF[indx], dif), ncol=3) } analyse2(DV, FF) # [,1] [,2] [,3] # [1,] 46.9 50.00784 -3.10784 # [2,] 42.7 52.51411 -9.81411 # [3,] 50.0 50.22578 -0.22578 # [4,] 47.8 50.29842 -2.49842 # [5,] 36.1 50.26210 -14.16210 # [6,] 44.5 50.55268 -6.05268 # [7,] 49.6 53.78541 -4.18541 # [8,] 44.7 50.08049 -5.38049

编辑2

两者都大于或小于50。

analyse3 <- function(DV, FF) { indx <- !( (DV > 50 & FF > 50) | (DV < 50 & FF < 50) ) dif <- DV[indx] - FF[indx] matrix(c(DV[indx], FF[indx], dif), ncol=3) }

R：“矩阵[i，1]中的错误：维数不正确”

1 个答案: