Is it expected to return just a few rows and a few columns? (e.g., first and last 2 rows, ...)
da <- DelayedArray(array(1, dim=c(20, 5, 4)))
trace(extract_array, quote(print(str(index))), exit=quote(print(returnValue())))
## Tracing function "extract_array" in environment
## <namespace:DelayedArray>
## Warning: Tracing only in the namespace; to untrace you will need:
## untrace("extract_array", where = getNamespace("DelayedArray"))
## [1] "extract_array"
## attr(,"package")
## [1] "DelayedArray"
> da
## Tracing extract_array(x, index) on entry
## List of 3
## $ : int(0)
## $ : int(0)
## $ : int(0)
## NULL
## Tracing extract_array(x@seed, index) on entry
## List of 3
## $ : int(0)
## $ : int(0)
## $ : int(0)
## NULL
## Tracing extract_array(x@seed, index) on exit
## <0 x 0 x 0 array of double>
## Tracing extract_array(x, index) on exit
## <0 x 0 x 0 array of double>
## <20 x 5 x 4> DelayedArray object of type "double":
## Tracing extract_array(x, index) on entry
## List of 3
## $ : int(0)
## $ : int(0)
## $ : int(0)
## NULL
## Tracing extract_array(x@seed, index) on entry
## List of 3
## $ : int(0)
## $ : int(0)
## $ : int(0)
## NULL
## Tracing extract_array(x@seed, index) on exit
## <0 x 0 x 0 array of double>
## ,,1
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on entry
## List of 3
## $ : NULL
## $ : NULL
## $ : int 1
## NULL
## Tracing extract_array(x@seed, index) on entry
## List of 3
## $ : NULL
## $ : NULL
## $ : int 1
## NULL
## Tracing extract_array(x@seed, index) on exit
## , , 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [5,] 1 1 1 1 1
## [6,] 1 1 1 1 1
## [7,] 1 1 1 1 1
## [8,] 1 1 1 1 1
## [9,] 1 1 1 1 1
## [10,] 1 1 1 1 1
## [11,] 1 1 1 1 1
## [12,] 1 1 1 1 1
## [13,] 1 1 1 1 1
## [14,] 1 1 1 1 1
## [15,] 1 1 1 1 1
## [16,] 1 1 1 1 1
## [17,] 1 1 1 1 1
## [18,] 1 1 1 1 1
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on exit
## , , 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [5,] 1 1 1 1 1
## [6,] 1 1 1 1 1
## [7,] 1 1 1 1 1
## [8,] 1 1 1 1 1
## [9,] 1 1 1 1 1
## [10,] 1 1 1 1 1
## [11,] 1 1 1 1 1
## [12,] 1 1 1 1 1
## [13,] 1 1 1 1 1
## [14,] 1 1 1 1 1
## [15,] 1 1 1 1 1
## [16,] 1 1 1 1 1
## [17,] 1 1 1 1 1
## [18,] 1 1 1 1 1
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on entry
## List of 2
## $ : int [1:4] 1 2 19 20
## $ : NULL
## NULL
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on exit
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## ... . . . . .
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1
## ...
## ,,4
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on entry
## List of 3
## $ : NULL
## $ : NULL
## $ : int 4
## NULL
## Tracing extract_array(x@seed, index) on entry
## List of 3
## $ : NULL
## $ : NULL
## $ : int 4
## NULL
## Tracing extract_array(x@seed, index) on exit
## , , 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [5,] 1 1 1 1 1
## [6,] 1 1 1 1 1
## [7,] 1 1 1 1 1
## [8,] 1 1 1 1 1
## [9,] 1 1 1 1 1
## [10,] 1 1 1 1 1
## [11,] 1 1 1 1 1
## [12,] 1 1 1 1 1
## [13,] 1 1 1 1 1
## [14,] 1 1 1 1 1
## [15,] 1 1 1 1 1
## [16,] 1 1 1 1 1
## [17,] 1 1 1 1 1
## [18,] 1 1 1 1 1
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on exit
## , , 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [5,] 1 1 1 1 1
## [6,] 1 1 1 1 1
## [7,] 1 1 1 1 1
## [8,] 1 1 1 1 1
## [9,] 1 1 1 1 1
## [10,] 1 1 1 1 1
## [11,] 1 1 1 1 1
## [12,] 1 1 1 1 1
## [13,] 1 1 1 1 1
## [14,] 1 1 1 1 1
## [15,] 1 1 1 1 1
## [16,] 1 1 1 1 1
## [17,] 1 1 1 1 1
## [18,] 1 1 1 1 1
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on entry
## List of 2
## $ : int [1:4] 1 2 19 20
## $ : NULL
## NULL
## Tracing extract_array(x, expand_Nindex_RangeNSBS(Nindex)) on exit
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## [3,] 1 1 1 1 1
## [4,] 1 1 1 1 1
## [,1] [,2] [,3] [,4] [,5]
## [1,] 1 1 1 1 1
## [2,] 1 1 1 1 1
## ... . . . . .
## [19,] 1 1 1 1 1
## [20,] 1 1 1 1 1