Limited Fortran Intrinsics Library

YAKL contains a limited library of Fortran intrinsic functions. Currently, they include the functions below. All computations-based (e.g., not tiny or epsilon) intrinsics called on SArray and FSArray objects are done in serial and can be performed inside parallel_for kernels. All computations-based intrinsics called on memDevice Array objects will invoke a kernel and cannot per performed inside parallel_for kernels.

• abs: Absolute value (element-wise) of an array
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
• all: Determines if all of the elements of a bool array are true
  • Same as the Fortran intrinsic except without the optional dim argument. Works on all Array, SArray, and FSArray objects.
• allocated: Determines if an array has been allocated
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
• any: Determines if any of the elements of a bool array are true
  • Same as the Fortran intrinsic except without the optional dim argument. Works on all Array, SArray, and FSArray objects.
• associated: Determines if an array has been allocated (same spirit as Fortran given different C++ semantics)
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
  • Recall that with YAKL Array objects, there is little meaningful difference between allocated and associated.
• count: Gives the number of true elements in a bool array
  • Same as the Fortran intrinsic except without the optional dim and kind arguments. Works on all Array, SArray, and FSArray objects.
• epsilon: Gives machine epsilon for the floating point type of the array or scalar passed in
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray, and scalar objects.
• huge: Gives the largest representable value for the arithmetic type of the array or scalar passed in
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray, and scalar objects.
• lbound: Gives the lower bound of the array passed in
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
  • For styleC Array objects and SArray objects: Without the dim argument, this returns an SArray object of rank 1. With the dim argument, zero-based indexing is expected.
  • For styleFortran Array objects and FSArray objects: Without the dim argument, this returns an FSArray object of rank 1 and lower bound of 1. With the dim argument, one-based indexing is expected.
• matinv: Matrix inverse for small arrays using Gaussian Elimination
  • This is not a Fortran intrinsic function, but it provides the inverse of square rank-2 SArray and FSArray matrix objects.
• matmul_cr and matmul_rc: Matrix multiplication using (column,row) and (row,column) format matrices
  • Same as the Fortran intrinsic. Works on SArray and FSArray objects only. FSArray objects must have the default lower bounds of 1 to be accepated by these routines.
• maxloc and minloc: Index of maximum and minimum value in an array
  • Same as the Fortran intrinsic without the optional dim, mask, kind, and back arguments. Only works on Array, SArray, and FSArray objects of rank 1.
  • When -DYAKL_B4B is turned on, device maxloc calculations are done serially on the host to preserve determinism
• maxval and minval: Maximum and minimum value in an array
  • Same as the Fortran intrinsic without the optional dim and mask arguments. Works on all Array, SArray, and FSArray objects.
• merge: Merge two arrays based on a bool mask array
  • Same as the Fortran intrinsic. Works on all Array, SArray, FSArray, and scalar objects.
• mod: Computes integer mod: a % b = a - ((int)(a/b) * b
  • Same as the Fortran intrinsic.
• pack: Packs an array into a single dimension with an optional mask.
  • Same as the Fortran intrinsic without the optional vector argument and only for rank-1 arrays. Works for all rank-1 Arrayobjects.
  • Does not work on SArray and FSArray objects because those require compile-time-known sizes, and the dimension sizes of the result of a pack operation cannot be known at compile time.
  • Calling pack on a memDevice Array leads to copying the inputs to the host, running pack on the host, and copying the results back to the device. This is because it is largely a serial operation.
• product: Computes the product over all elements of an array
  • Same as the Fortran intrinsic without the optional dim and mask parameters. Works on all Array, SArray, and FSArray objects.
• shape: Returns the shape an array as a rank-1 array of dimension sizes
  • Same as the Fortran intrinsic . Works on all Array, SArray, and FSArray objects.
  • For styleC Array objects and SArray objects, this returns an SArray object of rank 1.
  • For styleFortran Array objects and FSArray objects, this returns an FSArray object of rank 1 and lower bound of 1.
• sign: Applies the sign of the second argument to the first argument
  • Same as the Fortran intrinsic . Works on all Array, SArray, and FSArray objects.
• size: Gives the total elements of an array or the number of elements in a given dimension
  • Same as the Fortran intrinsic . Works on all Array, SArray, and FSArray objects.
  • For styleC Array objects and SArray objects: Without the dim argument, this returns an SArray object of rank 1. With the dim argument, zero-based indexing is expected.
  • For styleFortran Array objects and FSArray objects: Without the dim argument, this returns an FSArray object of rank 1 and lower bound of 1. With the dim argument, one-based indexing is expected.
• sum: Gives the sum of all elements in an array
  • Same as the Fortran intrinsic without the optional dim and mask parameters. Works on all Array, SArray, and FSArray objects.
• tiny: For floating point types, gives the smallest positive representable number. For integer types, gives the smallest overall representable number.
  • Same as the Fortran intrinsic for floating point types. Works on all Array, SArray, and FSArray objects.
• transpose: Transposes a rank-2 matrix
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
• ubound: Gives the upper bound of the array passed in
  • Same as the Fortran intrinsic. Works on all Array, SArray, and FSArray objects.
  • For styleC Array objects and SArray objects: Without the dim argument, this returns an SArray object of rank 1. With the dim argument, zero-based indexing is expected.
  • For styleFortran Array objects and FSArray objects: Without the dim argument, this returns an FSArray object of rank 1 and lower bound of 1. With the dim argument, one-based indexing is expected.