aboutsummaryrefslogtreecommitdiff
path: root/src/algebra/defaults.spad.pamphlet
blob: b50fee54aefc6e6706bccd9face5a4ad0908e815 (plain)
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
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
\documentclass{article}
\usepackage{axiom}
\begin{document}
\title{\$SPAD/src/algebra defaults.spad}
\author{Michael Monagan}
\maketitle
\begin{abstract}
\end{abstract}
\eject
\tableofcontents
\eject
\section{package REPSQ RepeatedSquaring}
<<package REPSQ RepeatedSquaring>>=
)abbrev package REPSQ RepeatedSquaring
++ Repeated Squaring
++ Description:
++ Implements exponentiation by repeated squaring
++ RelatedOperations: expt
-- the following package is only instantiated over %
-- thus shouldn't be cached. We prevent it
-- from being cached by declaring it to be mutableDomains

)bo PUSH('RepeatedSquaring, $mutableDomains) 

RepeatedSquaring(S): Exports == Implementation where
   S: SetCategory with 
	"*":(%,%)->%
	     ++ x*y returns the product of x and y
   Exports == with
     expt: (S,PositiveInteger) -> S 
       ++ expt(r, i) computes r**i  by repeated squaring
   Implementation == add
     x: S
     n: PositiveInteger
     expt(x, n) ==
        one? n => x
        odd?(n)$Integer=> x * expt(x*x,shift(n,-1) pretend PositiveInteger)
        expt(x*x,shift(n,-1) pretend PositiveInteger)

@
\section{package REPDB RepeatedDoubling}
<<package REPDB RepeatedDoubling>>=
)abbrev package REPDB RepeatedDoubling
++ Repeated Doubling
++ Integer multiplication by repeated doubling.
++ Description:
++ Implements multiplication by repeated addition
++ RelatedOperations: *
 
-- the following package is only instantiated over %
-- thus shouldn't be cached. We prevent it
-- from being cached by declaring it to be mutableDomains

)bo PUSH('RepeatedDoubling, $mutableDomains) 

RepeatedDoubling(S):Exports ==Implementation where
   S: SetCategory with 
	"+":(%,%)->%
		++ x+y returns the sum of x and y
   Exports == with
     double: (PositiveInteger,S) -> S 
       ++ double(i, r) multiplies r by i using repeated doubling.
   Implementation == add
     x: S
     n: PositiveInteger
     double(n,x) ==
        one? n => x
        odd?(n)$Integer =>
           x + double(shift(n,-1) pretend PositiveInteger,(x+x))
        double(shift(n,-1) pretend PositiveInteger,(x+x))

@
\section{package FLASORT FiniteLinearAggregateSort}
<<package FLASORT FiniteLinearAggregateSort>>=
)abbrev package FLASORT FiniteLinearAggregateSort
++ FiniteLinearAggregateSort
++ Sort package (in-place) for shallowlyMutable Finite Linear Aggregates
++ Author: Michael Monagan Sep/88
++ RelatedOperations: sort
++ Description:
++  This package exports 3 sorting algorithms which work over 
++  FiniteLinearAggregates.
-- the following package is only instantiated over %
-- thus shouldn't be cached. We prevent it
-- from being cached by declaring it to be mutableDomains
 
)bo PUSH('FiniteLinearAggregateSort, $mutableDomains) 

FiniteLinearAggregateSort(S, V): Exports == Implementation where
  S: Type
  V: FiniteLinearAggregate(S) with shallowlyMutable
 
  B ==> Boolean
  I ==> Integer
 
  Exports ==> with
    quickSort: ((S, S) -> B, V) -> V
      ++ quickSort(f, agg) sorts the aggregate agg with the ordering function
      ++ f using the quicksort algorithm.
    heapSort : ((S, S) -> B, V) -> V
      ++ heapSort(f, agg) sorts the aggregate agg with the ordering function
      ++ f using the heapsort algorithm.
    shellSort: ((S, S) -> B, V) -> V
      ++ shellSort(f, agg) sorts the aggregate agg with the ordering function
      ++ f using the shellSort algorithm.
 
  Implementation ==> add
    siftUp   : ((S, S) -> B, V, I, I) -> Void
    partition: ((S, S) -> B, V, I, I, I) -> I
    QuickSort: ((S, S) -> B, V, I, I) -> V
 
    quickSort(l, r) == QuickSort(l, r, minIndex r, maxIndex r)
 
    siftUp(l, r, i, n) ==
      t := qelt(r, i)
      while (j := 2*i+1) < n repeat
        if (k := j+1) < n and l(qelt(r, j), qelt(r, k)) then j := k
        if l(t,qelt(r,j)) then
           qsetelt_!(r, i, qelt(r, j))
           qsetelt_!(r, j, t)
           i := j
        else leave
 
    heapSort(l, r) ==
      not zero? minIndex r => error "not implemented"
      n := (#r)::I
      for k in shift(n,-1) - 1 .. 0 by -1 repeat siftUp(l, r, k, n)
      for k in n-1 .. 1 by -1 repeat
         swap_!(r, 0, k)
         siftUp(l, r, 0, k)
      r
 
    partition(l, r, i, j, k) ==
      -- partition r[i..j] such that r.s <= r.k <= r.t
      x := qelt(r, k)
      t := qelt(r, i)
      qsetelt_!(r, k, qelt(r, j))
      while i < j repeat
         if l(x,t) then
           qsetelt_!(r, j, t)
           j := j-1
           t := qsetelt_!(r, i, qelt(r, j))
         else (i := i+1; t := qelt(r, i))
      qsetelt_!(r, j, x)
      j
 
    QuickSort(l, r, i, j) ==
      n := j - i
      if one? n and l(qelt(r, j), qelt(r, i)) then swap_!(r, i, j)
      n < 2 => return r
      -- for the moment split at the middle item
      k := partition(l, r, i, j, i + shift(n,-1))
      QuickSort(l, r, i, k - 1)
      QuickSort(l, r, k + 1, j)
 
    shellSort(l, r) ==
      m := minIndex r
      n := maxIndex r
      -- use Knuths gap sequence: 1,4,13,40,121,...
      g := 1
      while g <= (n-m) repeat g := 3*g+1
      g := g quo 3
      while g > 0 repeat
         for i in m+g..n repeat
            j := i-g
            while j >= m and l(qelt(r, j+g), qelt(r, j)) repeat
               swap_!(r,j,j+g)
               j := j-g
         g := g quo 3
      r

@
\section{License}
<<license>>=
--Copyright (c) 1991-2002, The Numerical ALgorithms Group Ltd.
--All rights reserved.
--
--Redistribution and use in source and binary forms, with or without
--modification, are permitted provided that the following conditions are
--met:
--
--    - Redistributions of source code must retain the above copyright
--      notice, this list of conditions and the following disclaimer.
--
--    - Redistributions in binary form must reproduce the above copyright
--      notice, this list of conditions and the following disclaimer in
--      the documentation and/or other materials provided with the
--      distribution.
--
--    - Neither the name of The Numerical ALgorithms Group Ltd. nor the
--      names of its contributors may be used to endorse or promote products
--      derived from this software without specific prior written permission.
--
--THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS
--IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
--TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
--PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
--OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
--EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
--PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
--PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
--LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
--NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
--SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
@
<<*>>=
<<license>>

<<package REPSQ RepeatedSquaring>>
<<package REPDB RepeatedDoubling>>
<<package FLASORT FiniteLinearAggregateSort>>
 
@ 
\eject
\begin{thebibliography}{99}
\bibitem{1} nothing
\end{thebibliography}
\end{document}