subarray#
- swordfish.function.subarray()#
When a subset of the elements of a vector are needed in calculation, if we use script such as close[10:].avg(), a new vector close[10:] is generated with replicated data from the original vector close before the calculation is conducted. This not only consumes more memory but also takes time.
Function subarray generates a subarray of the original vector. It only records the pointer to the original vector together with the starting and ending positions of the subarray. As the system does not allocate a large block of memory to store the subarray, data replication does not occur. All read-only operations on vectors can be applied directly to a subarray.