Describes the sampling array dimensions associated with the binary file. The coordinates will be generated by gnuplot. A number must be specified for each dimension of the array. For example, `array=(10,20)` means the underlying sampling structure is two-dimensional with 10 points along the first (x) dimension and 20 points along the second (y) dimension. A negative number indicates that data should be read until the end of file. If there is only one dimension, the parentheses may be omitted. A colon can be used to separate the dimensions for multiple records. For example, `array=25:35` indicates there are two one-dimensional records in the file.
Note: Gnuplot version 4.2 used the syntax array=128x128 rather than array=(128,128). The older syntax is now deprecated, but may still work if your copy of gnuplot was built to support backwards compatibility.