Info Catalog cl: Predicates on Numbers cl: Numbers cl: Random Numbers

cl: Numerical Functions

 
 8.2 Numerical Functions
 =======================
 
 These functions perform various arithmetic operations on numbers.
 
  -- Function: cl-gcd &rest integers
      This function returns the Greatest Common Divisor of the arguments.
      For one argument, it returns the absolute value of that argument.
      For zero arguments, it returns zero.
 
  -- Function: cl-lcm &rest integers
      This function returns the Least Common Multiple of the arguments.
      For one argument, it returns the absolute value of that argument.
      For zero arguments, it returns one.
 
  -- Function: cl-isqrt integer
      This function computes the “integer square root” of its integer
      argument, i.e., the greatest integer less than or equal to the true
      square root of the argument.
 
  -- Function: cl-floor number &optional divisor
      With one argument, ‘cl-floor’ returns a list of two numbers: The
      argument rounded down (toward minus infinity) to an integer, and
      the “remainder” which would have to be added back to the first
      return value to yield the argument again.  If the argument is an
      integer X, the result is always the list ‘(X 0)’.  If the argument
      is a floating-point number, the first result is a Lisp integer and
      the second is a Lisp float between 0 (inclusive) and 1 (exclusive).
 
      With two arguments, ‘cl-floor’ divides NUMBER by DIVISOR, and
      returns the floor of the quotient and the corresponding remainder
      as a list of two numbers.  If ‘(cl-floor X Y)’ returns ‘(Q R)’,
      then ‘Q*Y + R = X’, with R between 0 (inclusive) and R (exclusive).
      Also, note that ‘(cl-floor X)’ is exactly equivalent to ‘(cl-floor
      X 1)’.
 
      This function is entirely compatible with Common Lisp’s ‘floor’
      function, except that it returns the two results in a list since
      Emacs Lisp does not support multiple-valued functions.
 
  -- Function: cl-ceiling number &optional divisor
      This function implements the Common Lisp ‘ceiling’ function, which
      is analogous to ‘floor’ except that it rounds the argument or
      quotient of the arguments up toward plus infinity.  The remainder
      will be between 0 and minus R.
 
  -- Function: cl-truncate number &optional divisor
      This function implements the Common Lisp ‘truncate’ function, which
      is analogous to ‘floor’ except that it rounds the argument or
      quotient of the arguments toward zero.  Thus it is equivalent to
      ‘cl-floor’ if the argument or quotient is positive, or to
      ‘cl-ceiling’ otherwise.  The remainder has the same sign as NUMBER.
 
  -- Function: cl-round number &optional divisor
      This function implements the Common Lisp ‘round’ function, which is
      analogous to ‘floor’ except that it rounds the argument or quotient
      of the arguments to the nearest integer.  In the case of a tie (the
      argument or quotient is exactly halfway between two integers), it
      rounds to the even integer.
 
  -- Function: cl-mod number divisor
      This function returns the same value as the second return value of
      ‘cl-floor’.
 
  -- Function: cl-rem number divisor
      This function returns the same value as the second return value of
      ‘cl-truncate’.
 
  -- Function: cl-parse-integer string &key start end radix junk-allowed
      This function implements the Common Lisp ‘parse-integer’ function.
      It parses an integer in the specified RADIX from the substring of
      STRING between START and END.  Any leading and trailing whitespace
      chars are ignored.  The function signals an error if the substring
      between START and END cannot be parsed as an integer, unless
      JUNK-ALLOWED is non-‘nil’.
 

Info Catalog cl: Predicates on Numbers cl: Numbers cl: Random Numbers