=> nil
- - Function: old-eq obj1 obj2
+ - Function: old-eq object1 object2
This function exists under XEmacs 20 and is exactly like `eq'
except that it suffers from the char-int confoundance disease. In
other words, it returns `t' if given a character and the
not check for overflow. Thus `(1+ 134217727)' may evaluate to
-134217728, depending on your hardware.
- - Function: 1+ number-or-marker
- This function returns NUMBER-OR-MARKER plus 1. For example,
+ - Function: 1+ number
+ This function returns NUMBER plus one. NUMBER may be a number,
+ character or marker. Markers and characters are converted to
+ integers.
+
+ For example,
(setq foo 4)
=> 4
more convenient and natural way to increment a variable is
`(incf foo)'.
- - Function: 1- number-or-marker
- This function returns NUMBER-OR-MARKER minus 1.
+ - Function: 1- number
+ This function returns NUMBER minus one. NUMBER may be a number,
+ character or marker. Markers and characters are converted to
+ integers.
- Function: abs number
This returns the absolute value of NUMBER.
- - Function: + &rest numbers-or-markers
+ - Function: + &rest numbers
This function adds its arguments together. When given no
arguments, `+' returns 0.
+ If any of the arguments are characters or markers, they are first
+ converted to integers.
+
(+)
=> 0
(+ 1)
(+ 1 2 3 4)
=> 10
- - Function: - &optional number-or-marker &rest other-numbers-or-markers
+ - Function: - &optional number &rest other-numbers
The `-' function serves two purposes: negation and subtraction.
When `-' has a single argument, the value is the negative of the
argument. When there are multiple arguments, `-' subtracts each of
- the OTHER-NUMBERS-OR-MARKERS from NUMBER-OR-MARKER, cumulatively.
- If there are no arguments, the result is 0.
+ the OTHER-NUMBERS from NUMBER, cumulatively. If there are no
+ arguments, an error is signaled.
+
+ If any of the arguments are characters or markers, they are first
+ converted to integers.
(- 10 1 2 3 4)
=> 0
(-)
=> 0
- - Function: * &rest numbers-or-markers
+ - Function: * &rest numbers
This function multiplies its arguments together, and returns the
product. When given no arguments, `*' returns 1.
+ If any of the arguments are characters or markers, they are first
+ converted to integers.
+
(*)
=> 1
(* 1)
(* 1 2 3 4)
=> 24
- - Function: / dividend divisor &rest divisors
- This function divides DIVIDEND by DIVISOR and returns the
- quotient. If there are additional arguments DIVISORS, then it
- divides DIVIDEND by each divisor in turn. Each argument may be a
- number or a marker.
+ - Function: / dividend &rest divisors
+ The `/' function serves two purposes: inversion and division. When
+ `/' has a single argument, the value is the inverse of the
+ argument. When there are multiple arguments, `/' divides DIVIDEND
+ by each of the DIVISORS, cumulatively, returning the quotient. If
+ there are no arguments, an error is signaled.
- If all the arguments are integers, then the result is an integer
- too. This means the result has to be rounded. On most machines,
- the result is rounded towards zero after each division, but some
+ If none of the arguments are floats, then the result is an integer.
+ This means the result has to be rounded. On most machines, the
+ result is rounded towards zero after each division, but some
machines may round differently with negative arguments. This is
because the Lisp function `/' is implemented using the C division
operator, which also permits machine-dependent rounding. As a
practical matter, all known machines round in the standard fashion.
+ If any of the arguments are characters or markers, they are first
+ converted to integers.
+
If you divide by 0, an `arith-error' error is signaled. (*Note
Errors::.)
=> 2
(/ 25 3 2)
=> 4
+ (/ 3.0)
+ => 0.3333333333333333
(/ -17 6)
=> -2
`fceiling', the nearest integer above; `ftruncate', the nearest integer
in the direction towards zero; `fround', the nearest integer.
- - Function: ffloor float
- This function rounds FLOAT to the next lower integral value, and
+ - Function: ffloor number
+ This function rounds NUMBER to the next lower integral value, and
returns that value as a floating point number.
- - Function: fceiling float
- This function rounds FLOAT to the next higher integral value, and
+ - Function: fceiling number
+ This function rounds NUMBER to the next higher integral value, and
returns that value as a floating point number.
- - Function: ftruncate float
- This function rounds FLOAT towards zero to an integral value, and
+ - Function: ftruncate number
+ This function rounds NUMBER towards zero to an integral value, and
returns that value as a floating point number.
- - Function: fround float
- This function rounds FLOAT to the nearest integral value, and
+ - Function: fround number
+ This function rounds NUMBER to the nearest integral value, and
returns that value as a floating point number.
\1f
supported (which is the normal state of affairs). They allow integers
as well as floating point numbers as arguments.
- - Function: sin arg
- - Function: cos arg
- - Function: tan arg
+ - Function: sin number
+ - Function: cos number
+ - Function: tan number
These are the ordinary trigonometric functions, with argument
measured in radians.
- - Function: asin arg
- The value of `(asin ARG)' is a number between -pi/2 and pi/2
- (inclusive) whose sine is ARG; if, however, ARG is out of range
- (outside [-1, 1]), then the result is a NaN.
+ - Function: asin number
+ The value of `(asin NUMBER)' is a number between -pi/2 and pi/2
+ (inclusive) whose sine is NUMBER; if, however, NUMBER is out of
+ range (outside [-1, 1]), then the result is a NaN.
+
+ - Function: acos number
+ The value of `(acos NUMBER)' is a number between 0 and pi
+ (inclusive) whose cosine is NUMBER; if, however, NUMBER is out of
+ range (outside [-1, 1]), then the result is a NaN.
- - Function: acos arg
- The value of `(acos ARG)' is a number between 0 and pi (inclusive)
- whose cosine is ARG; if, however, ARG is out of range (outside
- [-1, 1]), then the result is a NaN.
+ - Function: atan number &optional number2
+ The value of `(atan NUMBER)' is a number between -pi/2 and pi/2
+ (exclusive) whose tangent is NUMBER.
- - Function: atan arg
- The value of `(atan ARG)' is a number between -pi/2 and pi/2
- (exclusive) whose tangent is ARG.
+ If optional argument NUMBER2 is supplied, the function returns
+ `atan2(NUMBER,NUMBER2)'.
- - Function: sinh arg
- - Function: cosh arg
- - Function: tanh arg
+ - Function: sinh number
+ - Function: cosh number
+ - Function: tanh number
These are the ordinary hyperbolic trigonometric functions.
- - Function: asinh arg
- - Function: acosh arg
- - Function: atanh arg
+ - Function: asinh number
+ - Function: acosh number
+ - Function: atanh number
These are the inverse hyperbolic trigonometric functions.
- - Function: exp arg
- This is the exponential function; it returns e to the power ARG.
- e is a fundamental mathematical constant also called the base of
- natural logarithms.
+ - Function: exp number
+ This is the exponential function; it returns e to the power
+ NUMBER. e is a fundamental mathematical constant also called the
+ base of natural logarithms.
- - Function: log arg &optional base
- This function returns the logarithm of ARG, with base BASE. If
- you don't specify BASE, the base E is used. If ARG is negative,
- the result is a NaN.
+ - Function: log number &optional base
+ This function returns the logarithm of NUMBER, with base BASE. If
+ you don't specify BASE, the base E is used. If NUMBER is
+ negative, the result is a NaN.
- - Function: log10 arg
- This function returns the logarithm of ARG, with base 10. If ARG
- is negative, the result is a NaN. `(log10 X)' == `(log X 10)', at
- least approximately.
+ - Function: log10 number
+ This function returns the logarithm of NUMBER, with base 10. If
+ NUMBER is negative, the result is a NaN. `(log10 X)' == `(log X
+ 10)', at least approximately.
- Function: expt x y
This function returns X raised to power Y. If both arguments are
integers and Y is positive, the result is an integer; in this
case, it is truncated to fit the range of possible integer values.
- - Function: sqrt arg
- This returns the square root of ARG. If ARG is negative, the
- value is a NaN.
+ - Function: sqrt number
+ This returns the square root of NUMBER. If NUMBER is negative,
+ the value is a NaN.
- - Function: cube-root arg
- This returns the cube root of ARG.
+ - Function: cube-root number
+ This returns the cube root of NUMBER.
\1f
File: lispref.info, Node: Random Numbers, Prev: Math Functions, Up: Numbers
* Menu:
-* Basics: String Basics. Basic properties of strings and characters.
+* String Basics:: Basic properties of strings and characters.
* Predicates for Strings:: Testing whether an object is a string or char.
* Creating Strings:: Functions to allocate new strings.
* Predicates for Characters:: Testing whether an object is a character.