forked from Jstarfish/JavaKeeper
-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathbig.mjs
More file actions
924 lines (724 loc) · 20.1 KB
/
big.mjs
File metadata and controls
924 lines (724 loc) · 20.1 KB
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
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
/*
* big.js v5.2.2
* A small, fast, easy-to-use library for arbitrary-precision decimal arithmetic.
* Copyright (c) 2018 Michael Mclaughlin <M8ch88l@gmail.com>
* https://github.com/MikeMcl/big.js/LICENCE
*/
/************************************** EDITABLE DEFAULTS *****************************************/
// The default values below must be integers within the stated ranges.
/*
* The maximum number of decimal places (DP) of the results of operations involving division:
* div and sqrt, and pow with negative exponents.
*/
var DP = 20, // 0 to MAX_DP
/*
* The rounding mode (RM) used when rounding to the above decimal places.
*
* 0 Towards zero (i.e. truncate, no rounding). (ROUND_DOWN)
* 1 To nearest neighbour. If equidistant, round up. (ROUND_HALF_UP)
* 2 To nearest neighbour. If equidistant, to even. (ROUND_HALF_EVEN)
* 3 Away from zero. (ROUND_UP)
*/
RM = 1, // 0, 1, 2 or 3
// The maximum value of DP and Big.DP.
MAX_DP = 1E6, // 0 to 1000000
// The maximum magnitude of the exponent argument to the pow method.
MAX_POWER = 1E6, // 1 to 1000000
/*
* The negative exponent (NE) at and beneath which toString returns exponential notation.
* (JavaScript numbers: -7)
* -1000000 is the minimum recommended exponent value of a Big.
*/
NE = -7, // 0 to -1000000
/*
* The positive exponent (PE) at and above which toString returns exponential notation.
* (JavaScript numbers: 21)
* 1000000 is the maximum recommended exponent value of a Big.
* (This limit is not enforced or checked.)
*/
PE = 21, // 0 to 1000000
/**************************************************************************************************/
// Error messages.
NAME = '[big.js] ',
INVALID = NAME + 'Invalid ',
INVALID_DP = INVALID + 'decimal places',
INVALID_RM = INVALID + 'rounding mode',
DIV_BY_ZERO = NAME + 'Division by zero',
// The shared prototype object.
P = {},
UNDEFINED = void 0,
NUMERIC = /^-?(\d+(\.\d*)?|\.\d+)(e[+-]?\d+)?$/i;
/*
* Create and return a Big constructor.
*
*/
function _Big_() {
/*
* The Big constructor and exported function.
* Create and return a new instance of a Big number object.
*
* n {number|string|Big} A numeric value.
*/
function Big(n) {
var x = this;
// Enable constructor usage without new.
if (!(x instanceof Big)) return n === UNDEFINED ? _Big_() : new Big(n);
// Duplicate.
if (n instanceof Big) {
x.s = n.s;
x.e = n.e;
x.c = n.c.slice();
} else {
parse(x, n);
}
/*
* Retain a reference to this Big constructor, and shadow Big.prototype.constructor which
* points to Object.
*/
x.constructor = Big;
}
Big.prototype = P;
Big.DP = DP;
Big.RM = RM;
Big.NE = NE;
Big.PE = PE;
Big.version = '5.2.2';
return Big;
}
/*
* Parse the number or string value passed to a Big constructor.
*
* x {Big} A Big number instance.
* n {number|string} A numeric value.
*/
function parse(x, n) {
var e, i, nl;
// Minus zero?
if (n === 0 && 1 / n < 0) n = '-0';
else if (!NUMERIC.test(n += '')) throw Error(INVALID + 'number');
// Determine sign.
x.s = n.charAt(0) == '-' ? (n = n.slice(1), -1) : 1;
// Decimal point?
if ((e = n.indexOf('.')) > -1) n = n.replace('.', '');
// Exponential form?
if ((i = n.search(/e/i)) > 0) {
// Determine exponent.
if (e < 0) e = i;
e += +n.slice(i + 1);
n = n.substring(0, i);
} else if (e < 0) {
// Integer.
e = n.length;
}
nl = n.length;
// Determine leading zeros.
for (i = 0; i < nl && n.charAt(i) == '0';) ++i;
if (i == nl) {
// Zero.
x.c = [x.e = 0];
} else {
// Determine trailing zeros.
for (; nl > 0 && n.charAt(--nl) == '0';);
x.e = e - i - 1;
x.c = [];
// Convert string to array of digits without leading/trailing zeros.
for (e = 0; i <= nl;) x.c[e++] = +n.charAt(i++);
}
return x;
}
/*
* Round Big x to a maximum of dp decimal places using rounding mode rm.
* Called by stringify, P.div, P.round and P.sqrt.
*
* x {Big} The Big to round.
* dp {number} Integer, 0 to MAX_DP inclusive.
* rm {number} 0, 1, 2 or 3 (DOWN, HALF_UP, HALF_EVEN, UP)
* [more] {boolean} Whether the result of division was truncated.
*/
function round(x, dp, rm, more) {
var xc = x.c,
i = x.e + dp + 1;
if (i < xc.length) {
if (rm === 1) {
// xc[i] is the digit after the digit that may be rounded up.
more = xc[i] >= 5;
} else if (rm === 2) {
more = xc[i] > 5 || xc[i] == 5 &&
(more || i < 0 || xc[i + 1] !== UNDEFINED || xc[i - 1] & 1);
} else if (rm === 3) {
more = more || !!xc[0];
} else {
more = false;
if (rm !== 0) throw Error(INVALID_RM);
}
if (i < 1) {
xc.length = 1;
if (more) {
// 1, 0.1, 0.01, 0.001, 0.0001 etc.
x.e = -dp;
xc[0] = 1;
} else {
// Zero.
xc[0] = x.e = 0;
}
} else {
// Remove any digits after the required decimal places.
xc.length = i--;
// Round up?
if (more) {
// Rounding up may mean the previous digit has to be rounded up.
for (; ++xc[i] > 9;) {
xc[i] = 0;
if (!i--) {
++x.e;
xc.unshift(1);
}
}
}
// Remove trailing zeros.
for (i = xc.length; !xc[--i];) xc.pop();
}
} else if (rm < 0 || rm > 3 || rm !== ~~rm) {
throw Error(INVALID_RM);
}
return x;
}
/*
* Return a string representing the value of Big x in normal or exponential notation.
* Handles P.toExponential, P.toFixed, P.toJSON, P.toPrecision, P.toString and P.valueOf.
*
* x {Big}
* id? {number} Caller id.
* 1 toExponential
* 2 toFixed
* 3 toPrecision
* 4 valueOf
* n? {number|undefined} Caller's argument.
* k? {number|undefined}
*/
function stringify(x, id, n, k) {
var e, s,
Big = x.constructor,
z = !x.c[0];
if (n !== UNDEFINED) {
if (n !== ~~n || n < (id == 3) || n > MAX_DP) {
throw Error(id == 3 ? INVALID + 'precision' : INVALID_DP);
}
x = new Big(x);
// The index of the digit that may be rounded up.
n = k - x.e;
// Round?
if (x.c.length > ++k) round(x, n, Big.RM);
// toFixed: recalculate k as x.e may have changed if value rounded up.
if (id == 2) k = x.e + n + 1;
// Append zeros?
for (; x.c.length < k;) x.c.push(0);
}
e = x.e;
s = x.c.join('');
n = s.length;
// Exponential notation?
if (id != 2 && (id == 1 || id == 3 && k <= e || e <= Big.NE || e >= Big.PE)) {
s = s.charAt(0) + (n > 1 ? '.' + s.slice(1) : '') + (e < 0 ? 'e' : 'e+') + e;
// Normal notation.
} else if (e < 0) {
for (; ++e;) s = '0' + s;
s = '0.' + s;
} else if (e > 0) {
if (++e > n) for (e -= n; e--;) s += '0';
else if (e < n) s = s.slice(0, e) + '.' + s.slice(e);
} else if (n > 1) {
s = s.charAt(0) + '.' + s.slice(1);
}
return x.s < 0 && (!z || id == 4) ? '-' + s : s;
}
// Prototype/instance methods
/*
* Return a new Big whose value is the absolute value of this Big.
*/
P.abs = function () {
var x = new this.constructor(this);
x.s = 1;
return x;
};
/*
* Return 1 if the value of this Big is greater than the value of Big y,
* -1 if the value of this Big is less than the value of Big y, or
* 0 if they have the same value.
*/
P.cmp = function (y) {
var isneg,
x = this,
xc = x.c,
yc = (y = new x.constructor(y)).c,
i = x.s,
j = y.s,
k = x.e,
l = y.e;
// Either zero?
if (!xc[0] || !yc[0]) return !xc[0] ? !yc[0] ? 0 : -j : i;
// Signs differ?
if (i != j) return i;
isneg = i < 0;
// Compare exponents.
if (k != l) return k > l ^ isneg ? 1 : -1;
j = (k = xc.length) < (l = yc.length) ? k : l;
// Compare digit by digit.
for (i = -1; ++i < j;) {
if (xc[i] != yc[i]) return xc[i] > yc[i] ^ isneg ? 1 : -1;
}
// Compare lengths.
return k == l ? 0 : k > l ^ isneg ? 1 : -1;
};
/*
* Return a new Big whose value is the value of this Big divided by the value of Big y, rounded,
* if necessary, to a maximum of Big.DP decimal places using rounding mode Big.RM.
*/
P.div = function (y) {
var x = this,
Big = x.constructor,
a = x.c, // dividend
b = (y = new Big(y)).c, // divisor
k = x.s == y.s ? 1 : -1,
dp = Big.DP;
if (dp !== ~~dp || dp < 0 || dp > MAX_DP) throw Error(INVALID_DP);
// Divisor is zero?
if (!b[0]) throw Error(DIV_BY_ZERO);
// Dividend is 0? Return +-0.
if (!a[0]) return new Big(k * 0);
var bl, bt, n, cmp, ri,
bz = b.slice(),
ai = bl = b.length,
al = a.length,
r = a.slice(0, bl), // remainder
rl = r.length,
q = y, // quotient
qc = q.c = [],
qi = 0,
d = dp + (q.e = x.e - y.e) + 1; // number of digits of the result
q.s = k;
k = d < 0 ? 0 : d;
// Create version of divisor with leading zero.
bz.unshift(0);
// Add zeros to make remainder as long as divisor.
for (; rl++ < bl;) r.push(0);
do {
// n is how many times the divisor goes into current remainder.
for (n = 0; n < 10; n++) {
// Compare divisor and remainder.
if (bl != (rl = r.length)) {
cmp = bl > rl ? 1 : -1;
} else {
for (ri = -1, cmp = 0; ++ri < bl;) {
if (b[ri] != r[ri]) {
cmp = b[ri] > r[ri] ? 1 : -1;
break;
}
}
}
// If divisor < remainder, subtract divisor from remainder.
if (cmp < 0) {
// Remainder can't be more than 1 digit longer than divisor.
// Equalise lengths using divisor with extra leading zero?
for (bt = rl == bl ? b : bz; rl;) {
if (r[--rl] < bt[rl]) {
ri = rl;
for (; ri && !r[--ri];) r[ri] = 9;
--r[ri];
r[rl] += 10;
}
r[rl] -= bt[rl];
}
for (; !r[0];) r.shift();
} else {
break;
}
}
// Add the digit n to the result array.
qc[qi++] = cmp ? n : ++n;
// Update the remainder.
if (r[0] && cmp) r[rl] = a[ai] || 0;
else r = [a[ai]];
} while ((ai++ < al || r[0] !== UNDEFINED) && k--);
// Leading zero? Do not remove if result is simply zero (qi == 1).
if (!qc[0] && qi != 1) {
// There can't be more than one zero.
qc.shift();
q.e--;
}
// Round?
if (qi > d) round(q, dp, Big.RM, r[0] !== UNDEFINED);
return q;
};
/*
* Return true if the value of this Big is equal to the value of Big y, otherwise return false.
*/
P.eq = function (y) {
return !this.cmp(y);
};
/*
* Return true if the value of this Big is greater than the value of Big y, otherwise return
* false.
*/
P.gt = function (y) {
return this.cmp(y) > 0;
};
/*
* Return true if the value of this Big is greater than or equal to the value of Big y, otherwise
* return false.
*/
P.gte = function (y) {
return this.cmp(y) > -1;
};
/*
* Return true if the value of this Big is less than the value of Big y, otherwise return false.
*/
P.lt = function (y) {
return this.cmp(y) < 0;
};
/*
* Return true if the value of this Big is less than or equal to the value of Big y, otherwise
* return false.
*/
P.lte = function (y) {
return this.cmp(y) < 1;
};
/*
* Return a new Big whose value is the value of this Big minus the value of Big y.
*/
P.minus = P.sub = function (y) {
var i, j, t, xlty,
x = this,
Big = x.constructor,
a = x.s,
b = (y = new Big(y)).s;
// Signs differ?
if (a != b) {
y.s = -b;
return x.plus(y);
}
var xc = x.c.slice(),
xe = x.e,
yc = y.c,
ye = y.e;
// Either zero?
if (!xc[0] || !yc[0]) {
// y is non-zero? x is non-zero? Or both are zero.
return yc[0] ? (y.s = -b, y) : new Big(xc[0] ? x : 0);
}
// Determine which is the bigger number. Prepend zeros to equalise exponents.
if (a = xe - ye) {
if (xlty = a < 0) {
a = -a;
t = xc;
} else {
ye = xe;
t = yc;
}
t.reverse();
for (b = a; b--;) t.push(0);
t.reverse();
} else {
// Exponents equal. Check digit by digit.
j = ((xlty = xc.length < yc.length) ? xc : yc).length;
for (a = b = 0; b < j; b++) {
if (xc[b] != yc[b]) {
xlty = xc[b] < yc[b];
break;
}
}
}
// x < y? Point xc to the array of the bigger number.
if (xlty) {
t = xc;
xc = yc;
yc = t;
y.s = -y.s;
}
/*
* Append zeros to xc if shorter. No need to add zeros to yc if shorter as subtraction only
* needs to start at yc.length.
*/
if ((b = (j = yc.length) - (i = xc.length)) > 0) for (; b--;) xc[i++] = 0;
// Subtract yc from xc.
for (b = i; j > a;) {
if (xc[--j] < yc[j]) {
for (i = j; i && !xc[--i];) xc[i] = 9;
--xc[i];
xc[j] += 10;
}
xc[j] -= yc[j];
}
// Remove trailing zeros.
for (; xc[--b] === 0;) xc.pop();
// Remove leading zeros and adjust exponent accordingly.
for (; xc[0] === 0;) {
xc.shift();
--ye;
}
if (!xc[0]) {
// n - n = +0
y.s = 1;
// Result must be zero.
xc = [ye = 0];
}
y.c = xc;
y.e = ye;
return y;
};
/*
* Return a new Big whose value is the value of this Big modulo the value of Big y.
*/
P.mod = function (y) {
var ygtx,
x = this,
Big = x.constructor,
a = x.s,
b = (y = new Big(y)).s;
if (!y.c[0]) throw Error(DIV_BY_ZERO);
x.s = y.s = 1;
ygtx = y.cmp(x) == 1;
x.s = a;
y.s = b;
if (ygtx) return new Big(x);
a = Big.DP;
b = Big.RM;
Big.DP = Big.RM = 0;
x = x.div(y);
Big.DP = a;
Big.RM = b;
return this.minus(x.times(y));
};
/*
* Return a new Big whose value is the value of this Big plus the value of Big y.
*/
P.plus = P.add = function (y) {
var t,
x = this,
Big = x.constructor,
a = x.s,
b = (y = new Big(y)).s;
// Signs differ?
if (a != b) {
y.s = -b;
return x.minus(y);
}
var xe = x.e,
xc = x.c,
ye = y.e,
yc = y.c;
// Either zero? y is non-zero? x is non-zero? Or both are zero.
if (!xc[0] || !yc[0]) return yc[0] ? y : new Big(xc[0] ? x : a * 0);
xc = xc.slice();
// Prepend zeros to equalise exponents.
// Note: reverse faster than unshifts.
if (a = xe - ye) {
if (a > 0) {
ye = xe;
t = yc;
} else {
a = -a;
t = xc;
}
t.reverse();
for (; a--;) t.push(0);
t.reverse();
}
// Point xc to the longer array.
if (xc.length - yc.length < 0) {
t = yc;
yc = xc;
xc = t;
}
a = yc.length;
// Only start adding at yc.length - 1 as the further digits of xc can be left as they are.
for (b = 0; a; xc[a] %= 10) b = (xc[--a] = xc[a] + yc[a] + b) / 10 | 0;
// No need to check for zero, as +x + +y != 0 && -x + -y != 0
if (b) {
xc.unshift(b);
++ye;
}
// Remove trailing zeros.
for (a = xc.length; xc[--a] === 0;) xc.pop();
y.c = xc;
y.e = ye;
return y;
};
/*
* Return a Big whose value is the value of this Big raised to the power n.
* If n is negative, round to a maximum of Big.DP decimal places using rounding
* mode Big.RM.
*
* n {number} Integer, -MAX_POWER to MAX_POWER inclusive.
*/
P.pow = function (n) {
var x = this,
one = new x.constructor(1),
y = one,
isneg = n < 0;
if (n !== ~~n || n < -MAX_POWER || n > MAX_POWER) throw Error(INVALID + 'exponent');
if (isneg) n = -n;
for (;;) {
if (n & 1) y = y.times(x);
n >>= 1;
if (!n) break;
x = x.times(x);
}
return isneg ? one.div(y) : y;
};
/*
* Return a new Big whose value is the value of this Big rounded using rounding mode rm
* to a maximum of dp decimal places, or, if dp is negative, to an integer which is a
* multiple of 10**-dp.
* If dp is not specified, round to 0 decimal places.
* If rm is not specified, use Big.RM.
*
* dp? {number} Integer, -MAX_DP to MAX_DP inclusive.
* rm? 0, 1, 2 or 3 (ROUND_DOWN, ROUND_HALF_UP, ROUND_HALF_EVEN, ROUND_UP)
*/
P.round = function (dp, rm) {
var Big = this.constructor;
if (dp === UNDEFINED) dp = 0;
else if (dp !== ~~dp || dp < -MAX_DP || dp > MAX_DP) throw Error(INVALID_DP);
return round(new Big(this), dp, rm === UNDEFINED ? Big.RM : rm);
};
/*
* Return a new Big whose value is the square root of the value of this Big, rounded, if
* necessary, to a maximum of Big.DP decimal places using rounding mode Big.RM.
*/
P.sqrt = function () {
var r, c, t,
x = this,
Big = x.constructor,
s = x.s,
e = x.e,
half = new Big(0.5);
// Zero?
if (!x.c[0]) return new Big(x);
// Negative?
if (s < 0) throw Error(NAME + 'No square root');
// Estimate.
s = Math.sqrt(x + '');
// Math.sqrt underflow/overflow?
// Re-estimate: pass x coefficient to Math.sqrt as integer, then adjust the result exponent.
if (s === 0 || s === 1 / 0) {
c = x.c.join('');
if (!(c.length + e & 1)) c += '0';
s = Math.sqrt(c);
e = ((e + 1) / 2 | 0) - (e < 0 || e & 1);
r = new Big((s == 1 / 0 ? '1e' : (s = s.toExponential()).slice(0, s.indexOf('e') + 1)) + e);
} else {
r = new Big(s);
}
e = r.e + (Big.DP += 4);
// Newton-Raphson iteration.
do {
t = r;
r = half.times(t.plus(x.div(t)));
} while (t.c.slice(0, e).join('') !== r.c.slice(0, e).join(''));
return round(r, Big.DP -= 4, Big.RM);
};
/*
* Return a new Big whose value is the value of this Big times the value of Big y.
*/
P.times = P.mul = function (y) {
var c,
x = this,
Big = x.constructor,
xc = x.c,
yc = (y = new Big(y)).c,
a = xc.length,
b = yc.length,
i = x.e,
j = y.e;
// Determine sign of result.
y.s = x.s == y.s ? 1 : -1;
// Return signed 0 if either 0.
if (!xc[0] || !yc[0]) return new Big(y.s * 0);
// Initialise exponent of result as x.e + y.e.
y.e = i + j;
// If array xc has fewer digits than yc, swap xc and yc, and lengths.
if (a < b) {
c = xc;
xc = yc;
yc = c;
j = a;
a = b;
b = j;
}
// Initialise coefficient array of result with zeros.
for (c = new Array(j = a + b); j--;) c[j] = 0;
// Multiply.
// i is initially xc.length.
for (i = b; i--;) {
b = 0;
// a is yc.length.
for (j = a + i; j > i;) {
// Current sum of products at this digit position, plus carry.
b = c[j] + yc[i] * xc[j - i - 1] + b;
c[j--] = b % 10;
// carry
b = b / 10 | 0;
}
c[j] = (c[j] + b) % 10;
}
// Increment result exponent if there is a final carry, otherwise remove leading zero.
if (b) ++y.e;
else c.shift();
// Remove trailing zeros.
for (i = c.length; !c[--i];) c.pop();
y.c = c;
return y;
};
/*
* Return a string representing the value of this Big in exponential notation to dp fixed decimal
* places and rounded using Big.RM.
*
* dp? {number} Integer, 0 to MAX_DP inclusive.
*/
P.toExponential = function (dp) {
return stringify(this, 1, dp, dp);
};
/*
* Return a string representing the value of this Big in normal notation to dp fixed decimal
* places and rounded using Big.RM.
*
* dp? {number} Integer, 0 to MAX_DP inclusive.
*
* (-0).toFixed(0) is '0', but (-0.1).toFixed(0) is '-0'.
* (-0).toFixed(1) is '0.0', but (-0.01).toFixed(1) is '-0.0'.
*/
P.toFixed = function (dp) {
return stringify(this, 2, dp, this.e + dp);
};
/*
* Return a string representing the value of this Big rounded to sd significant digits using
* Big.RM. Use exponential notation if sd is less than the number of digits necessary to represent
* the integer part of the value in normal notation.
*
* sd {number} Integer, 1 to MAX_DP inclusive.
*/
P.toPrecision = function (sd) {
return stringify(this, 3, sd, sd - 1);
};
/*
* Return a string representing the value of this Big.
* Return exponential notation if this Big has a positive exponent equal to or greater than
* Big.PE, or a negative exponent equal to or less than Big.NE.
* Omit the sign for negative zero.
*/
P.toString = function () {
return stringify(this);
};
/*
* Return a string representing the value of this Big.
* Return exponential notation if this Big has a positive exponent equal to or greater than
* Big.PE, or a negative exponent equal to or less than Big.NE.
* Include the sign for negative zero.
*/
P.valueOf = P.toJSON = function () {
return stringify(this, 4);
};
// Export
export var Big = _Big_();
export default Big;