uses packed arrays if possible in the internal representation of expr.


  • To use ToPackedArray, you first need to load the Developer Utilities Package using Needs["Developer`"].
  • Using ToPackedArray will not change results generated by the Wolfram Language, but can enhance speed of execution and reduce memory usage.
  • ToPackedArray is effectively used automatically by many functions that generate large lists.
  • ToPackedArray will successfully pack full lists of any depth containing machinesized integers and machinesized approximate real and complex numbers.
  • ToPackedArray[expr,type] will when possible convert entries in expr to be of the specified type.
  • Possible types are: Integer, Real, and Complex.
  • Only machinesized numbers can be stored in packed form.
  • The option Tolerance->tol can be used to specify when small numerical values can be ignored in conversion to more restrictive types, and when they must prevent conversion to packed form.