Categories of Intrinsic Functions

Generic intrinsic functions can be divided into categories, as shown in the following table:

Categories of Intrinsic Functions

Category Subcategory Description
Numeric Computation Elemental functions that perform type conversions or simple numeric operations: ABS, AIMAG, AINT, AMAX0, AMIN0, ANINT, CEILING, CMPLX, CONJG, DBLE, DCMPLX, DFLOAT, DIM, DNUM, DPROD, DREAL, FLOAT, FLOOR, IFIX, IMAG, INT, INUM, JNUM, MAX, MAX1, MIN, MIN1, MOD, MODULO, NINT, QCMPLX, QEXT, QFLOAT, QNUM, QREAL, REAL, RNUM, SIGN, SNGL, ZEXT
Nonelemental functions that perform type conversions or simple numeric operations: ILEN, RAN
  Manipulation1 Elemental functions that return values related to the components of the model values associated with the actual value of the argument: EXPONENT, FRACTION, NEAREST, RRSPACING, SCALE, SET_EXPONENT, SPACING
Inquiry1 Functions that return scalar values from the models associated with the type and kind parameters of their arguments2: DIGITS, EPSILON, HUGE, MAXEXPONENT, MINEXPONENT, PRECISION, RADIX, RANGE, SIZEOF, TINY
Transformational Functions that perform vector and matrix multiplication: DOT_PRODUCT, MATMUL
System Functions that return information about a process or processor: MCLOCK, SECNDS
Kind type Functions that return kind type parameters: KIND, SELECTED_CHAR_KIND, SELECTED_INT_KIND, SELECTED_REAL_KIND
Mathematical Elemental functions that perform mathematical operations: ACOS, ACOSD, ACOSH, ASIN, ASIND, ASINH, ATAN, ATAN2, ATAN2D, ATAND, ATANH, COS, COSD, COSH, COTAN, COTAND, EXP, LOG, LOG10, SIN, SIND, SINH, SQRT, TAN, TAND, TANH
Bit Manipulation Elemental functions that perform single-bit processing, logical and shift operations, and allow bit subfields to be referenced: AND, BTEST, DSHIFTL, DSHIFTR, IAND, IBCHNG, IBCLR, IBITS, IBSET, IEOR, IOR, ISHA, ISHC, ISHFT, ISHFTC, ISHL, IXOR, LSHIFT, NOT, OR, RSHIFT, SHIFTL, SHIFTR, XOR
Inquiry Function that lets you determine parameter s (the bit size) in the bit model3: BIT_SIZE
Representation Elemental functions that return information on bit representation of integers: LEADZ, POPCNT, POPPAR, TRAILZ
Character Comparison Elemental functions that make a lexical comparison of the character-string arguments and return a default logical result: LGE, LGT, LLE, LLT
Conversion Elemental functions that take character arguments and return integer, ASCII, or character values4: ACHAR, CHAR, IACHAR, ICHAR
String handling Functions that perform operations on character strings, return lengths of arguments, and search for certain arguments: Elemental: ADJUSTL, ADJUSTR, INDEX, LEN_TRIM, SCAN, VERIFY; Nonelemental: REPEAT, TRIM
Inquiry Functions that return the length of an argument or information about command-line arguments: COMMAND_ARGUMENT_COUNT, IARG, IARGC, LEN, NARGS, NUMARG
Array Construction Functions that construct new arrays from the elements of existing array: Elemental: MERGE; Nonelemental: PACK, SPREAD, UNPACK
Inquiry Functions that let you determine if an array argument is allocated, and return the size or shape of an array, and the lower and upper bounds of subscripts along each dimension: ALLOCATED, LBOUND, SHAPE, SIZE, UBOUND
Location Transformational functions that find the geometric locations of the maximum and minimum values of an array: MAXLOC, MINLOC
Manipulation Transformational functions that shift an array, transpose an array, or change the shape of an array: CSHIFT, EOSHIFT, RESHAPE, TRANSPOSE
Reduction Transformational functions that perform operations on arrays. The functions "reduce" elements of a whole array to produce a scalar result, or they can be applied to a specific dimension of an array to produce a result array with a rank reduced by one: ALL, ANY, COUNT, MAXVAL, MINVAL, PRODUCT, SUM
Miscellaneous Functions that do the following:
  • Check for pointer association (ASSOCIATED)
  • Return an address (BADDRESS or IADDR)
  • Return the size of a level of the memory cache (CACHESIZE)5
  • Check for end-of-file (EOF)
  • Return error functions (ERF and ERFC)
  • Return the class of a floating-point argument (FP_CLASS)
  • Return the INTEGER KIND that will hold an address (INT_PTR_KIND)
  • Test for Not-a-Number values (ISNAN)
  • Return the internal address of a storage item (LOC)
  • Return a logical value of an argument (LOGICAL)
  • Allocate memory (MALLOC)
  • Return the upper 64 bits of a 128-bit unsigned result (MULT_HIGH)5
  • Return the upper 64 bits of a 128-bit signed result (MULT_HIGH_SIGNED)5
  • Return a new line character (NEW_LINE)
  • Return a disassociated pointer (NULL)
  • Check for argument presence (PRESENT)
  • Convert a bit pattern (TRANSFER)
  • Check for end-of-file condition (IS_IOSTAT_END)
  • Check for end-of-record condition (IS_IOSTAT_EOR)
1 All of the numeric manipulation, and many of the numeric inquiry functions are defined by the model sets for integers and reals.
2 The value of the argument does not have to be defined.
3 For more information on bit functions, see Bit functions.

4 The Intel® Fortran processor character set is ASCII, so ACHAR = CHAR and IACHAR = ICHAR.
5 i64 only

The following table summarizes the generic intrinsic functions and indicates whether they are elemental, inquiry, or transformational functions. Optional arguments are shown within square brackets.

Some intrinsic functions are specific with no generic association. These functions are listed below.

Summary of Generic Intrinsic Functions

Generic Function Class Value Returned
ABS (A) E The absolute value of an argument
ACHAR (I) E The character in the specified position of the ASCII character set
ACOS (X) E The arccosine (in radians) of the argument
ACOSD (X) E The arccosine (in degrees) of the argument
ACOSH (X) E The hyperbolic arccosine of the argument
ADJUSTL (STRING) E The specified string with leading blanks removed and placed at the end of the string
ADJUSTR (STRING) E The specified string with trailing blanks removed and placed at the beginning of the string
AIMAG (Z) E The imaginary part of a complex argument
AINT (A [,KIND]) E A real value truncated to a whole number
ALL (MASK [,DIM]) T .TRUE. if all elements of the masked array are true
ALLOCATED (ARRAY) I The allocation status of the argument array
AMAX0 (A1, A2 [, A3,...]) E The maximum value in a list of integers (returned as a real value)
AMIN0 (A1, A2 [, A3,...]) E The minimum value in a list of integers (returned as a real value)
AND (I, J) E See IAND
ANINT (A [, KIND]) E A real value rounded to a whole number
ANY (MASK [, DIM]) T .TRUE. if any elements of the masked array are true
ASIN (X) E The arcsine (in radians) of the argument
ASIND (X) E The arcsine (in degrees) of the argument
ASINH (X) E The hyperbolic arcsine of the argument
ASSOCIATED (POINTER [,TARGET]) I .TRUE. if the pointer argument is associated or the pointer is associated with the specified target
ATAN (X) E The arctangent (in radians) of the argument
ATAN2 (Y, X) E The arctangent (in radians) of the arguments
ATAN2D (Y, X) E The arctangent (in degrees) of the arguments
ATAND (X) E The arctangent (in degrees) of the argument
ATANH (X) E The hyperbolic arctangent of the argument
BADDRESS (X) I The address of the argument
BIT_SIZE (I) I The number of bits (s) in the bit model
BTEST (I, POS) E .TRUE. if the specified position of argument I is one
CEILING (A [,KIND]) E The smallest integer greater than or equal to the argument value
CHAR (I [,KIND]) E The character in the specified position of the processor character set
COMMAND_ARGUMENT_COUNT () I The number of command arguments
CONJG (Z) E The conjugate of a complex number
COS (X) E The cosine of the argument, which is in radians
COSD (X) E The cosine of the argument, which is in degrees
COSH (X) E The hyperbolic cosine of the argument
COTAN (X) E The cotangent of the argument, which is in radians
COTAND (X) E The cotangent of the argument, which is in degrees
COUNT (MASK [,DIM] [,KIND]) T The number of .TRUE. elements in the argument array
CSHIFT (ARRAY, SHIFT [,DIM]) T An array that has the elements of the argument array circularly shifted
DBLE (A) E The corresponding double precision value of the argument
DFLOAT (A) E The corresponding double precision value of the integer argument
DIGITS (X) I The number of significant digits in the model for the argument
DIM (X, Y) E The positive difference between the two arguments
DOT_PRODUCT (VECTOR_A, VECTOR_B) T The dot product of two rank-one arrays (also called a vector multiply function)
DREAL (A) E The corresponding double-precision value of the double complex argument
DSHIFTL (ILEFT, IRIGHT, ISHIFT) E The upper (leftmost) 64 bits of a left-shifted 128-bit integer
DSHIFTR (ILEFT, IRIGHT, ISHIFT) E The lower (rightmost) 64 bits of a right-shifted 128-bit integer
EOF (A) I .TRUE. or .FALSE. depending on whether a file is beyond the end-of-file record
EOSHIFT (ARRAY, SHIFT [,BOUNDARY] [,DIM]) T An array that has the elements of the argument array end-off shifted
EPSILON (X) I The number that is almost negligible when compared to one
ERF (X) E The error function of an argument
ERFC (X) E The complementary error function of an argument
EXP (X) E The exponential ex for the argument x
EXPONENT (X) E The value of the exponent part of a real argument
FLOAT (X) E The corresponding real value of the integer argument
FLOOR (A [,KIND]) E The largest integer less than or equal to the argument value
FP_CLASS (X) E The class of the IEEE floating-point argument
FRACTION (X) E The fractional part of a real argument
HUGE (X) I The largest number in the model for the argument
IACHAR (C) E The position of the specified character in the ASCII character set
IADDR (X) E See BADDRESS
IAND (I, J) E The logical AND of the two arguments
IBCLR (I, POS) E The specified position of argument I cleared (set to zero)
IBCHNG (I, POS) E The reversed value of a specified bit
IBITS (I, POS, LEN) E The specified substring of bits of argument I
IBSET (I, POS) E The specified bit in argument I set to one
ICHAR (C [, KIND]) E The position of the specified character in the processor character set
IEOR (I, J) E The logical exclusive OR of the corresponding bit arguments
IFIX (X) E The corresponding integer value of the real argument rounded as if it were an implied conversion in an assignment
ILEN (I) I The length (in bits) in the two's complement representation of an integer
IMAG (Z) E See AIMAG
INDEX (STRING, SUBSTRING [, BACK] [,KIND]) E The position of the specified substring in a character expression
INT (A [, KIND]) E The corresponding integer value (truncated) of the argument
IOR (I, J) E The logical inclusive OR of the corresponding bit arguments
IS_IOSTAT_END (I) E .TRUE. if an end-of-file condition exists.
IS_IOSTAT_EOR (I) E .TRUE. if an end-of-record condition exists.
ISHA (I, SHIFT) E Argument I shifted left or right by a specified number of bits
ISHC (I, SHIFT) E Argument I rotated left or right by a specified number of bits
ISHFT (I, SHIFT) E The logical end-off shift of the bits in argument I
ISHFTC (I, SHIFT [,SIZE]) E The logical circular shift of the bits in argument I
ISHL (I, SHIFT) E Argument I logically shifted left or right by a specified number of bits
ISNAN (X) E Tests for Not-a-Number (NaN) values
IXOR (I, J) E See IEOR
KIND (X) I The kind type parameter of the argument
LBOUND (ARRAY [,DIM] [,KIND]) I The lower bounds of an array (or one of its dimensions)
LEADZ (I) E The number of leading zero bits in an integer
LEN (STRING [,KIND]) I The length (number of characters) of the argument character string
LEN_TRIM (STRING [,KIND]) E The length of the specified string without trailing blanks
LGE (STRING_A, STRING_B) E A logical value determined by a > or = comparison of the arguments
LGT (STRING_A, STRING_ B) E A logical value determined by a > comparison of the arguments
LLE (STRING_A, STRING_B) E A logical value determined by a < or = comparison of the arguments
LLT (STRING_A, STRING_B) E A logical value determined by a < comparison of the arguments
LOC (A) I The internal address of the argument.
LOG (X) E The natural logarithm of the argument
LOG10 (X) E The common logarithm (base 10) of the argument
LOGICAL (L [,KIND]) E The logical value of the argument converted to a logical of type KIND
LSHIFT (I, POSITIVE_SHIFT) E See ISHFT
LSHFT (I, POSITIVE_SHIFT) E Same as LSHIFT; see ISHFT
MALLOC (I) E The starting address for the block of memory allocated
MATMUL (MATRIX_A, MATRIX_B) T The result of matrix multiplication (also called a matrix multiply function)
MAX (A1, A2 [, A3,...]) E The maximum value in the set of arguments
MAX1 (A1, A2 [, A3,...]) E The maximum value in the set of real arguments (returned as an integer)
MAXEXPONENT (X) I The maximum exponent in the model for the argument
MAXLOC (ARRAY [,DIM] [,MASK] [,KIND]) T The rank-one array that has the location of the maximum element in the argument array
MAXVAL (ARRAY [,DIM] [,MASK]) T The maximum value of the elements in the argument array
MERGE (TSOURCE, FSOURCE, MASK) E An array that is the combination of two conformable arrays (under a mask)
MIN (A1, A2 [, A3,...]) E The minimum value in the set of arguments
MIN1 (A1, A2 [, A3,...]) E The minimum value in the set of real arguments (returned as an integer)
MINEXPONENT (X) I The minimum exponent in the model for the argument
MINLOC (ARRAY [,DIM] [,MASK] [,KIND]) T The rank-one array that has the location of the minimum element in the argument array
MINVAL (ARRAY [,DIM] [,MASK]) T The minimum value of the elements in the argument array
MOD (A, P) E The remainder of the arguments (has the sign of the first argument)
MODULO (A, P) E The modulo of the arguments (has the sign of the second argument)
NEAREST (X, S) E The nearest different machine-representable number in a given direction
NEW_LINE (A) I A new line character
NINT (A [,KIND]) E A real value rounded to the nearest integer
NOT (I) E The logical complement of the argument
NULL ([MOLD]) T A disassociated pointer
OR (I, J) E See IOR
PACK (ARRAY, MASK [,VECTOR]) T A packed array of rank one (under a mask)
POPCNT (I) E The number of 1 bits in the integer argument
POPPAR (I) E The parity of the integer argument
PRECISION (X) I The decimal precision (real or complex) of the argument
PRESENT (A) I .TRUE. if an actual argument has been provided for an optional dummy argument
PRODUCT (ARRAY [,DIM] [,MASK]) T The product of the elements of the argument array
QEXT (A) E The corresponding REAL(16) precision value of the argument
QFLOAT (A) E The corresponding REAL(16) precision value of the integer argument
RADIX (X) I The base of the model for the argument
RANGE (X) I The decimal exponent range of the model for the argument
REAL (A [, KIND]) E The corresponding real value of the argument
REPEAT (STRING, NCOPIES) T The concatenation of zero or more copies of the specified string
RESHAPE (SOURCE, SHAPE [,PAD] [,ORDER]) T An array that has a different shape than the argument array, but the same elements
RRSPACING (X) E The reciprocal of the relative spacing near the argument
RSHIFT (I, NEGATIVE_SHIFT) E See ISHFT
RSHFT (I, NEGATIVE_SHIFT) E Same as RSHIFT; see ISHFT
SCALE (X, I) E The value of the exponent part (of the model for the argument) changed by a specified value
SCAN (STRING, SET [,BACK] [,KIND]) E The position of the specified character (or set of characters) within a string
SELECTED_CHAR_KIND (NAME) T The value of the kind type parameter of the character set named by the argument
SELECTED_INT_KIND (R) T The integer kind parameter of the argument
SELECTED_REAL_KIND ([P] [, R]) T The real kind parameter of the argument; one of the optional arguments must be specified
SET_EXPONENT (X, I) E The value of the exponent part (of the model for the argument) set to a specified value
SHAPE (SOURCE [,KIND]) I The shape (rank and extents) of an array or scalar
SHIFTL (IVALUE, ISHIFT) E Argument IVALUE shifted left by a specified number of bits
SHIFTR (IVALUE, ISHIFT) E Argument IVALUE shifted right by a specified number of bits
SIGN (A, B) E A value with the sign transferred from its second argument
SIN (X) E The sine of the argument, which is in radians
SIND (X) E The sine of the argument, which is in degreess
SINH (X) E The hyperbolic sine of the argument
SIZE (ARRAY [,DIM] [,KIND]) I The size (total number of elements) of the argument array (or one of its dimensions)
SIZEOF (X) I The bytes of storage used by the argument
SNGL (X) E The corresponding real value of the argument
SPACING (X) E The value of the absolute spacing of model numbers near the argument
SPREAD (SOURCE, DIM, NCOPIES) T A replicated array that has an added dimension
SQRT (X) E The square root of the argument
SUM (ARRAY [,DIM] [,MASK]) T The sum of the elements of the argument array
TAN (X) E The tangent of the argument, which is in radians
TAND (X) E The tangent of the argument, which is in degrees
TANH (X) E The hyperbolic tangent of the argument
TINY (X) I The smallest positive number in the model for the argument
TRAILZ (I) E The number of trailing zero bits in an integer
TRANSFER (SOURCE, MOLD [,SIZE]) T The bit pattern of SOURCE converted to the type and kind parameters of MOLD
TRANSPOSE (MATRIX) T The matrix transpose for the rank-two argument array
TRIM (STRING) T The argument with trailing blanks removed
UBOUND (ARRAY [,DIM] [,KIND]) I The upper bounds of an array (or one of its dimensions)
UNPACK (VECTOR, MASK, FIELD) T An array (under a mask) unpacked from a rank-one array
VERIFY (STRING, SET [,BACK] [,KIND]) E The position of the first character in a string that does not appear in the given set of characters
XOR (I, J) E See IEOR
ZEXT (X [,KIND]) E A zero-extended value of the argument
Key to Classes

E-Elemental
I-Inquiry
T-Transformational

The following table lists specific functions that have no generic function associated with them and indicates whether they are elemental, nonelemental, or inquiry functions. Optional arguments are shown within square brackets.

Specific Functions with No Generic Association

Generic Function Class Value Returned
CACHESIZE (N)1 I The size of a level of the memory cache
CMPLX (X [,Y] [,KIND]) E The corresponding complex value of the argument
DCMPLX (X, Y) E The corresponding double complex value of the argument
DNUM (I) E The corresponding double-precision value of a character string
DPROD (X, Y) E The double-precision product of two real arguments
DREAL (A) E The corresponding double-precision value of the double-complex argument
IARG ( ) I See IARGC
IARGC ( ) I The index of the last command-line argument
INT_PTR_KIND ( ) I The INTEGER kind that will hold an address
INUM (I) E The corresponding INTEGER(2) value of a character string
JNUM (I) E The corresponding INTEGER(4) value of a character string
MCLOCK ( ) I The sum of the current process’s user time and the user and system time of all its child processes
MULT_HIGH (I, J)1 E The upper (leftmost) 64 bits of the 128-bit unsigned result
MULT_HIGH_SIGNED (I, J)1 E The upper (leftmost) 64 bits of the 128-bit signed result
NARGS ( ) I The total number of command-line arguments, including the command
NUMARG ( ) I See IARGC
QCMPLX (X, Y) E The corresponding COMPLEX(16) value of the argument
QNUM (I) E The corresponding REAL(16) value of a character string
QREAL (A) E The corresponding REAL(16) value of the real part of a COMPLEX(16) argument
RAN (I) N The next number from a sequence of pseudorandom numbers (uniformly distributed in the range 0 to 1)
RNUM (I) E The corresponding REAL(4) value of a character string
SECNDS (X) E The system time of day (or elapsed time) as a floating-point value in seconds
Key to Classes

E-Elemental
I-Inquiry
N-Nonelemental

1 i64 only