# Q to R

This section describes language features that start with Q or R.

Parent topic: A to Z Reference

- QCMPLX
  Elemental Intrinsic Function (Specific): Converts an argument to COMPLEX(16) type. This function cannot be passed as an actual argument.
- QEXT
  Elemental Intrinsic Function (Generic): Converts a number to quad precision (REAL(16)) type.
- QFLOAT
  Elemental Intrinsic Function (Generic): Converts an integer to quad precision (REAL(16)) type.
- QNUM
  Elemental Intrinsic Function (Specific): Converts a character string to a REAL(16) value. This function cannot be passed as an actual argument.
- QRANSET
  Portability Subroutine: Sets the seed for a sequence of pseudo-random numbers.
- QREAL
  Elemental Intrinsic Function (Specific): Converts the real part of a COMPLEX(16) argument to REAL(16) type. This is a specific function that has no generic function associated with it. It cannot be passed as an actual argument.
- QSORT
  Portability Subroutine: Performs a quick sort on an array of rank one.
- RADIX
  Inquiry Intrinsic Function (Generic): Returns the base of the model representing numbers of the same type and kind as the argument.
- RAISEQQ
  Portability Function: Sends a signal to the executing program.
- RAN
  Nonelemental Intrinsic Function (Specific): Returns the next number from a sequence of pseudorandom numbers of uniform distribution over the range 0 to 1. This is a specific function that has no generic function associated with it. It cannot be passed as an actual argument.
- RAND, RANDOM
  Portability Functions: Return real random numbers in the range 0.0 to 1.0, not including the end points.
- RANDOM Subroutine
  Portability Subroutine: Returns a pseudorandom number greater than or equal to zero and less than one from the uniform distribution.
- RANDOM_INIT
  Intrinsic Subroutine: Initializes the pseudorandom number generator used by RANDOM_NUMBER.
- RANDOM_NUMBER
  Intrinsic Subroutine: Returns one pseudorandom number or an array of such numbers.
- RANDOM_SEED
  Intrinsic Subroutine (Generic): Changes or queries the seed (starting point) for the pseudorandom number generator used by intrinsic subroutine RANDOM_NUMBER. Intrinsic subroutines cannot be passed as actual arguments.
- RANDU
  Intrinsic Subroutine (Generic): Computes a pseudorandom number as a single-precision value. Intrinsic subroutines cannot be passed as actual arguments.
- RANF Intrinsic Procedure
  Elemental Intrinsic Function (Generic): Generates a random number between 0.0 and RAND_MAX. This function must not be passed as an actual argument. RANF can be used as an intrinsic procedure or as a portability routine. It is an intrinsic procedure unless you specify USE IFPORT.
- RANF Portability Routine
  Portability Function: Generates a random number between 0.0 and RAND_MAX. RANF can be used as a portability routine or as an intrinsic procedure. It is an intrinsic procedure unless you specify USE IFPORT.
- RANGE
  Inquiry Intrinsic Function (Generic): Returns the decimal exponent range in the model representing numbers with the same kind parameter as the argument.
- RANGET
  Portability Subroutine: Returns the current seed.
- RANK
  Inquiry Intrinsic Function (Generic): Returns the rank of a data object.
- RANSET
  Portability Subroutine: Sets the seed for the random number generator.
- READ Statement
  Statement: Transfers input data from external sequential, direct-access, or internal records.
- REAL Directive
  General Compiler Directive: Specifies the default real kind.
- REAL Function
  Elemental Intrinsic Function (Generic): Converts a value to real type.
- REAL Statement
  Statement: Specifies the REAL data type.
- RECORD
  Statement: Declares a record structure as an entity with a name.
- RECURSIVE and NON_RECURSIVE
  Keywords: RECURSIVE specifies that a subroutine or function can call itself directly or indirectly. NON_RECURSIVE specifies that a subroutine or function does not call itself directly or indirectly.
- REDUCE
  Transformational Intrinsic Function (Generic): Performs general array reduction.
- REDUCTION
  Parallel Directive Clause: Performs a reduction operation on the specified variables.
- %REF
  Built-in Function: Changes the form of an actual argument. Passes the argument by reference. In Intel® Fortran, passing by reference is the default.
- RENAME
  Portability Function: Renames a file.
- RENAMEFILEQQ
  Portability Function: Renames a file or directory.
- REPEAT
  Transformational Intrinsic Function (Generic): Concatenates several copies of a string.
- REQUIRES
  OpenMP* Fortran Compiler Directive: Lists the features that an implementation must support so that the program compiles and runs correctly. This feature is only available for ifx.
- RESHAPE
  Transformational Intrinsic Function (Generic): Constructs an array with a different shape from the argument array.
- RESULT
  Keyword: Specifies a name for a function result.
- RETURN
  Statement: Transfers control from a subprogram to the calling program unit.
- REWIND
  Statement: Positions a sequential or direct access file at the beginning of the file (the initial point). It takes one of the following forms:
- REWRITE
  Statement: Rewrites the current record.
- RINDEX
  Portability Function: Locates the index of the last occurrence of a substring within a string.
- RNUM
  Elemental Intrinsic Function (Specific): Converts a character string to a REAL(4) value. This function cannot be passed as an actual argument.
- RRSPACING
  Elemental Intrinsic Function (Generic): Returns the reciprocal of the relative spacing of model numbers near the argument value.
- RSHIFT
  Elemental Intrinsic Function (Generic): Shifts the bits in an integer right by a specified number of positions. This is the same as specifying ISHFT with a negative shift.
- RTC
  Portability Function: Returns the number of seconds elapsed since a specific Greenwich mean time.
- RUNQQ
  Portability Function: Executes another program and waits for it to complete.