/usr/share/calc/help/cmp is in apcalc-common 2.12.5.0-1build1.
This file is owned by root:root, with mode 0o644.
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1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 | NAME
cmp - compare two values of certain simple or object types
SYNOPSIS
cmp(x, y)
TYPES
If x is an object of type xx, or x is not an object and y is an object
of type xx, the function xx_rel has to have been defined; any
further conditions on x and y, and the type of the returned
value depends on the definition of xx_rel.
For non-object x and y:
x any
y any
return if x and y are both real: -1, 0, or 1
if x and y are both numbers but not both real:
-1, 0, 1, -1+1i, 1i, 1+1i, -1-1i, -1i, or 1-1i
if x and y are both strings: -1, 0, or 1
all other cases: the null value
DESCRIPTION
x and y both real: cmp(x, y) = sgn(x - y), i.e. -1, 0, or 1
according as x < y, x == y, or x > y
x and y both numbers, at least one being complex:
cmp(x,y) = sgn(re(x) - re(y)) + sgn(im(x) - im(y)) * 1i
x and y both strings: successive characters are compared until either
different characters are encountered or at least one string is
completed. If the comparison ends because of different characters,
cmp(x,y) = 1 or -1 according as the greater character is in x or y.
If all characters compared in both strings are equal, then
cmp(x,y) = -1, 0 or 1 according as the length of x is less than,
equal to, or greater than the length of y. (This comparison
is performed via the strcmp() libc function.)
objects: comparisons of objects are usually intended for some total or
partial ordering and appropriate definitions of cmp(a,b) may
make use of comparison of numerical or string components.
definitions using comparison of numbers or strings are usually
appropriate. For example, after
obj point {x,y};
if points with real components are to be partially ordered by their
euclidean distance from the origin, an appropriate point_rel
function may be that given by
define point_rel(a,b) = sgn(a.x^2 + a.y^2 - b.x^2 - b.y^2);
A total "lexicographic" ordering is that given by:
define point_rel(a,b) {
if (a.y != b.y)
return sgn(a.y - b.y);
return (a.x - b.x);
}
A comparison function that compares points analogously to
cmp(a,b) for real and complex numbers is that given by
define point_rel(P1, P2) {
return obj point = {sgn(P1.x-P2.x), sgn(P1.y-P2.y)};
}
The range of this function is the set of nine points with zero
or unit components.
Some properties of cmp(a,b) for real or complex a and b are:
cmp(a + c, b + c) = cmp(a, b)
cmp(a, b) == 0 if and only if a == b
cmp(b, a) = -cmp(a, b)
if c is real or pure imaginary, cmp(c * a, c * b) = c * cmp(a,b)
Then a function that defines "b is between a and c" in an often useful
sense is
define between(a,b,c) = (cmp(a,b) == cmp(b,c)).
For example, in this sense, 3 + 4i is between 1 + 5i and 4 + 2i.
Note that using cmp to compare non-object values of different types,
for example, cmp(2, "2"), returns the null value.
EXAMPLE
; print cmp(3,4), cmp(4,3), cmp(4,4), cmp("a","b"), cmp("abcd","abc")
-1 1 0 -1 1
; print cmp(3,4i), cmp(4,4i), cmp(5,4i), cmp(-5,4i), cmp(-4i,5), cmp(-4i,-5)
1-1i 1-1i 1-1i -1-1i -1-1i 1-1i
; print cmp(3i,4i), cmp(4i,4i), cmp(5i,4i), cmp(3+4i,5), cmp(3+4i,-5)
-1i 0 1i -1+1i 1+1i
; print cmp(3+4i,3+4i), cmp(3+4i,3-4i), cmp(3+4i,2+3i), cmp(3+4i,-4-5i)
0 1i 1+1i 1+1i
LIMITS
none
LINK LIBRARY
FLAG qrel(NUMBER *q1, NUMBER *q2)
FLAG zrel(ZVALUE z1, ZVALUE z2)
SEE ALSO
sgn, test, operator
## Copyright (C) 1999 Landon Curt Noll
##
## Calc is open software; you can redistribute it and/or modify it under
## the terms of the version 2.1 of the GNU Lesser General Public License
## as published by the Free Software Foundation.
##
## Calc is distributed in the hope that it will be useful, but WITHOUT
## ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
## or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General
## Public License for more details.
##
## A copy of version 2.1 of the GNU Lesser General Public License is
## distributed with calc under the filename COPYING-LGPL. You should have
## received a copy with calc; if not, write to Free Software Foundation, Inc.
## 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
##
## @(#) $Revision: 30.1 $
## @(#) $Id: cmp,v 30.1 2007/03/16 11:10:42 chongo Exp $
## @(#) $Source: /usr/local/src/bin/calc/help/RCS/cmp,v $
##
## Under source code control: 1994/10/20 02:52:30
## File existed as early as: 1994
##
## chongo <was here> /\oo/\ http://www.isthe.com/chongo/
## Share and enjoy! :-) http://www.isthe.com/chongo/tech/comp/calc/
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