-
Notifications
You must be signed in to change notification settings - Fork 2
/
Copy pathmath.html
437 lines (435 loc) · 11.9 KB
/
math.html
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
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
<html dir="ltr">
<head>
<meta content="text/html; charset=UTF-8" http-equiv="Content-Type"/>
<title>Arc: Math operations</title>
<link rel="shortcut icon" href="/assets/favicon.png">
<link rel="stylesheet" type="text/css" href="code.css">
<link href="/assets/bootstrap.css" rel="stylesheet">
</head>
<body style='margin:12px 50px 0'>
<div class="navbar navbar-inverse">
<div class="navbar-inner">
<ul class="nav navbar-nav">
<li><a href="/ref/">Arc 3.1</a>
<li><a href="http://tryarc.org">Try it</a></li>
<li><a href="http://github.com/arclanguage/anarki">Get it</a></li>
<li><a href="http://ycombinator.com/arc/tut.txt">Tutorial</a></li>
<li><a href="http://arclanguage.org/forum">Forum</a></li>
</ul>
</div>
</div> <!-- end of navbar -->
<div class="links">Previous: <a href="macro.html">Macros</a>
Up: <a href="index.html">Contents</a>
Next: <a href="predicates.html">Predicates</a>
</div>
<h1 class="links">Math operations</h1>
<h2>Math operations</h2>
The math operations of Arc are fairly limited. Many expected
operations, such as trigonometry, are missing.
<p><table class='arc'>
<tr>
<td class='arc'><a name='*'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>*</span> <span class='args'>args</span>
<div class='desc'>Multiplication.</div>
</td>
<td class='arc'><pre>
>(* 2 3)
<span class="return">6
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='%2b'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>+</span> <span class='args'>args</span>
<div class='desc'>Addition. This operator also performs string and list
concatenation.</div>
</td>
<td class='arc'><pre>
>(+ 1 2 3)
<span class="return">6
</span></pre>
<pre>
>(+ "ab" "c" "de")
<span class="return">"abcde"
</span></pre>
<pre>
>(+ '(1 2) '(3 4) '(5))
<span class="return">(1 2 3 4 5)
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='-'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>-</span> <span class='args'>args</span>
<div class='desc'>Subtraction.</div>
</td>
<td class='arc'><pre>
>(- 3 2)
<span class="return">1
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='/'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>/</span> <span class='args'>args</span>
<div class='desc'>Division</div>
</td>
<td class='arc'><pre>
>(/ 1 2)
<span class="return">1/2
</span></pre>
<pre>
>(/ 1.0 2)
<span class="return">0.5
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='cos'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>cos</span> <span class='args'>arg</span>
<div class='desc'>Cosine function. New in arc3.</div>
</td>
<td class='arc'><pre>
>(cos 3.14)
<span class="return">-0.9999987317275395
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='expt'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>expt</span> <span class='args'>base exponent</span>
<div class='desc'>Exponentiation.</div>
</td>
<td class='arc'><pre>
>(expt 2 3)
<span class="return">8
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='log'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>log</span> <span class='args'>arg</span>
<div class='desc'>Natuarl logarithm function. New in arc3.</div>
</td>
<td class='arc'><pre>
>(log 100)
<span class="return">4.605170185988092
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='mod'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>mod</span> <span class='args'>dividend divisor</span>
<div class='desc'> </div>
</td>
<td class='arc'><pre>
>(mod 10 3)
<span class="return">1
</span></pre>
<pre>
>(mod -10 3)
<span class="return">2
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='rand'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>rand</span> <span class='args'>[max] </span>
<div class='desc'>Returns a random number between 0 and 1, or between 0 and
the specified integer (excluding the integer).</div>
</td>
<td class='arc'><pre>
>(rand 10)
<span class="return">5
</span></pre>
<pre>
>(rand)
<span class="return">0.08773957245280758
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='sin'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>sin</span> <span class='args'>arg</span>
<div class='desc'>Sine function. New in arc3.</div>
</td>
<td class='arc'><pre>
>(sin 3.14)
<span class="return">0.0015926529164868282
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='sqrt'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>sqrt</span> <span class='args'>number</span>
<div class='desc'>Square root operation</div>
</td>
<td class='arc'><pre>
>(sqrt 2)
<span class="return">1.4142135623730951
</span></pre>
<pre>
>(sqrt -1)
<span class="return">0+1i
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='tan'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>tan</span> <span class='args'>arg</span>
<div class='desc'>Tangent function. New in arc3.</div>
</td>
<td class='arc'><pre>
>(tan 3.14)
<span class="return">-0.001592654936407223
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='trunc'></a>
<img src='foundation.gif' title='Foundation'/>
<span class='op'>trunc</span> <span class='args'>number</span>
<div class='desc'>Truncates to an integer. Was 'truncate' in arc0.</div>
</td>
<td class='arc'><pre>
>(trunc 1.9)
<span class="return">1
</span></pre>
<pre>
>(trunc -1.1)
<span class="return">-1
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='number'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>number</span> <span class='args'>n</span>
<div class='desc'>Tests if n is a number (int or num).</div>
</td>
<td class='arc'><pre>
>(number 3.14)
<span class="return">t
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='positive'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>positive</span> <span class='args'>x</span>
<div class='desc'>Tests if x is a number and is positive (>= 0). This fails on complex numbers.</div>
</td>
<td class='arc'><pre>
>(positive 0)
<span class="return">nil
</span></pre>
<pre>
>(positive -2)
<span class="return">nil
</span></pre>
<pre>
>(positive "a")
<span class="return">nil
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='abs'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>abs</span> <span class='args'>n</span>
<div class='desc'>Returns the absolute value.</div>
</td>
<td class='arc'><pre>
>(abs -3)
<span class="return">3
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='round'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>round</span> <span class='args'>n</span>
<div class='desc'>Rounds n to the nearest value. Halfs are rounded to the nearest even number.</div>
</td>
<td class='arc'><pre>
>(round 1/2)
<span class="return">0
</span></pre>
<pre>
>(round 1.5)
<span class="return">2
</span></pre>
<pre>
>(round 0.4)
<span class="return">0
</span></pre>
<pre>
>(round -1.5)
<span class="return">-2
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='roundup'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>roundup</span> <span class='args'>n</span>
<div class='desc'>Rounds n to the nearest value. Halfs are rounded away from zero.</div>
</td>
<td class='arc'><pre>
>(roundup 1/2)
<span class="return">1
</span></pre>
<pre>
>(roundup 1.5)
<span class="return">2
</span></pre>
<pre>
>(roundup 0.4)
<span class="return">0
</span></pre>
<pre>
>(roundup -1.5)
<span class="return">-2
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='nearest'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>nearest</span> <span class='args'>n quantum</span>
<div class='desc'>Rounds down to the nearest multiple of n. Renamed in arc3.</div>
</td>
<td class='arc'><pre>
>(nearest 3.14 0.1)
<span class="return">3.1
</span></pre>
<pre>
>(nearest -5 10)
<span class="return">-10
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='median'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>median</span> <span class='args'>list</span>
<div class='desc'>Returns the median of the list (the element at the midpoint of the list when sorted highest-to-lowest). Takes the earlier element for an even-length list.</div>
</td>
<td class='arc'><pre>
>(median '(1 5 3 2 4))
<span class="return">3
</span></pre>
<pre>
>(median '("dog" "cat" "bird") (median '(1 2 3 4)))
<span class="stdout">Error: median: arity mismatch;
the expected number of argu
ments does not match the given number
expected: 1
given:
2
arguments...:
'("dog" "cat" "bird" . nil)
2
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='med'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>med</span> <span class='args'>list [compare-fn]</span>
<div class='desc'>Returns the median of the list (the element at the midpoint of the list when sorted according to compare-fn). Takes the later element for an even-length list. New in arc3.</div>
</td>
<td class='arc'><pre>
>(med '(1 5 3 2 4))
<span class="return">3
</span></pre>
<pre>
>(med '("dog" "cat" "bird") (med '(1 2 3 4)))
<span class="stdout">Error: Function call on inappropriate object 2 ("bird" "cat"
)
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='avg'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>avg</span> <span class='args'>numbers</span>
<div class='desc'>Computes the average of a list of numbers.</div>
</td>
<td class='arc'><pre>
>(avg '(1+2i 0.4))
<span class="return">0.7+1.0i
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='even'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>even</span> <span class='args'>n</span>
<div class='desc'>Tests if n is even. Argument n must be an integer.</div>
</td>
<td class='arc'><pre>
>(even 1)
<span class="return">nil
</span></pre>
<pre>
>(even 2)
<span class="return">t
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='odd'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>odd</span> <span class='args'>n</span>
<div class='desc'>Tests if n is odd. Argument n must be an integer.</div>
</td>
<td class='arc'><pre>
>(odd 1)
<span class="return">t
</span></pre>
<pre>
>(odd 2)
<span class="return">nil
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='max'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>max</span> <span class='args'>[arg ...]</span>
<div class='desc'>Returns the maximum arg. The args must be comparable with >.</div>
</td>
<td class='arc'><pre>
>(max 10 -3 5)
<span class="return">10
</span></pre>
<pre>
>(max "cat" "dog" "bird")
<span class="return">"dog"
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='min'></a>
<img src='proc.gif' title='Procedure'/>
<span class='op'>min</span> <span class='args'>[arg ...]</span>
<div class='desc'>Returns the minimum arg. The args must be comparable with <.</div>
</td>
<td class='arc'><pre>
>(min 10 -3 5)
<span class="return">-3
</span></pre>
<pre>
>(min "cat" "dog" "bird")
<span class="return">"bird"
</span></pre>
</td></tr>
<tr>
<td class='arc'><a name='multiple'></a>
<img src='proc.gif' title='Procedure'/>
<img src='predicate.gif' title='Predicate'/>
<span class='op'>multiple</span> <span class='args'>x base</span>
<div class='desc'>Tests if <code>x</code> is a multiple of <code>base</code>.</div>
</td>
<td class='arc'><pre>
>(multiple 10 5)
<span class="return">t
</span></pre>
<pre>
>(multiple 11 5)
<span class="return">nil
</span></pre>
</td></tr>
</table>
<p>
Copyright 2008 Ken Shirriff.
</body>
</html>