pindex {ComplexHeatmap} | R Documentation

## Get Values in a Matrix by Pair-wise Indices

### Description

Get Values in a Matrix by Pair-wise Indices

### Usage

    pindex(m, i, j)

### Arguments

`m` | A matrix or a 3-dimension array.
`i` | Row indices or the indices in the first dimension.
`j` | Column indicies or the indices in the second dimension.

### Value

If `m` is a matrix, the value returned is a vector `c(m[i1, j1], m[i2, j2], ...)`'.

If `m` is an array, the value returned is a matrix `rbind(m[i1, j1, ], m[i2, j2, ], ...)`'.

### Examples

    m = matrix(rnorm(100), 10)
    m2 = m[m > 0]
    ind = do.call("rbind", lapply(1:10, function(ci) {
        i = which(m[, ci] > 0)
        cbind(i = i, j = rep(ci, length(i)))
    }))
    pindex(m, ind[, 1], ind[, 2])
    identical(pindex(m, ind[, 1], ind[, 2]), m[m > 0])

    # 3d array
    arr = array(1:27, dim = c(3, 3, 3))
    pindex(arr, 1:2, 2:3)
    identical(pindex(arr, 1:2, 2:3),
       rbind(arr[1, 2, ], arr[2, 3, ]))

[Package ComplexHeatmap version 2.3.4 Index]