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Initial development of BCD integers
author Paul (paul.d.anderson@comcast.net)
date Thu, 18 Mar 2010 18:10:25 -0700
parents a984d3056cc4
children
comparison
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3:bfda0b347c07 4:b37c218c1442
32 32
33 module decimal.math; 33 module decimal.math;
34 34
35 import decimal.decimal; 35 import decimal.decimal;
36 import decimal.context; 36 import decimal.context;
37 //import std.math;
37 38
38 public: 39 public:
39 40
40 //-------------------------------- 41 //--------------------------------
41 // 42 //
42 // CONSTANTS 43 // CONSTANTS
43 // 44 //
44 //-------------------------------- 45 //--------------------------------
46
47 /+ public Decimal HALF;
48 public Decimal ONE = Decimal(1);
49 public Decimal ZERO = Decimal(0);
50
51 static {
52 HALF = Decimal("0.5");
53 }+/
45 54
46 /** 55 /**
47 * Returns the value of e to the default precision. 56 * Returns the value of e to the default precision.
48 */ 57 */
49 Decimal e() { 58 Decimal e() {
57 Decimal e(uint precision) { 66 Decimal e(uint precision) {
58 Decimal result; 67 Decimal result;
59 return result; 68 return result;
60 } 69 }
61 70
71 /+
62 /** 72 /**
63 * Returns the value of pi to the default precision. 73 * Returns the value of pi to the default precision.
64 */ 74 */
65 Decimal pi() { 75 Decimal pi() {
66 Decimal result; 76 Decimal ONE = Decimal(1);
67 return result; 77 writeln("1 = ", ONE);
68 } 78 Decimal TWO = Decimal(2);
69 79 writeln("2 = ", TWO);
80 Decimal HALF = Decimal(0.5);
81 writeln("0.5 = ", HALF);
82 Decimal x = sqrt(TWO);
83 writeln("x = ", x);
84 Decimal y = sqrt(x);
85 writeln("y = ", y);
86 Decimal p = TWO + x;
87 writeln("p = ", p);
88 x = y;
89 int i = 0;
90 while (true) {
91 writeln("i = ", i);
92 x = HALF * (x + ONE/x);
93 writeln("step 1");
94 Decimal np = p * ((x + ONE)/(y + ONE));
95 writeln("step 2");
96 writeln("np = ", np);
97 if (p == np) return p;
98 writeln("step 3");
99 p = np;
100 writeln("step 4");
101 x = sqrt(x);
102 writeln("step 5");
103 // writeln("x = ", x);
104 Decimal oox = ONE/x;
105 // writeln("ONE/x = ", oox);
106 // writeln ("x + ONE/x = ", x + oox);
107 // Decimal t1 = oox + x;
108 // writeln("t1 = ", t1);
109 // Decimal t1 = x + oox; // ONE + oox; //x + x; // + ONE/x;
110 writeln("step 6");
111 // Decimal t2 = (y * x) + ONE; ///x; //ONE / (y + ONE);
112 // y = ONE/x + y * x;
113 writeln("step 7");
114 y = (ONE/x + y * x) / (y + ONE); //t1 / t2;
115 writeln("step 8");
116 i++;
117 // break;
118 }
119 return p;
120 }
121
122 unittest {
123 write("pi....");
124 writeln("pi = ", pi());
125 }
126 +/
70 /** 127 /**
71 * Returns the value of pi to the specified precision. 128 * Returns the value of pi to the specified precision.
72 */ 129 */
73 Decimal pi(uint precision) {; 130 Decimal pi(uint precision) {;
74 Decimal result; 131 Decimal result;
75 return result; 132 return result;
76 } 133 }
77 134
78 /** 135 /**
79 * Returns the square root of the argument to the default precision. 136 * Returns the square root of the argument to the current precision.
80 */ 137 */
81 Decimal sqrt(Decimal arg) { 138 Decimal sqrt(Decimal arg) {
82 Decimal result; 139 return sqrt(arg, context.precision);
83 return result; 140 }
84 } 141
142
143 unittest {
144 write("sqrt.....");
145 Decimal dcm = Decimal(4);
146 assert(sqrt(dcm) == Decimal(2));
147 writeln("sqrt(2) = ", sqrt(Decimal(2)));
148 }
85 149
86 /** 150 /**
87 * Returns the square root of the argument to the specified precision. 151 * Returns the square root of the argument to the specified precision.
88 */ 152 */
89 Decimal sqrt(Decimal arg, uint precision) { 153 Decimal sqrt(Decimal arg, uint precision) {
90 Decimal result; 154 pushContext();
91 return result; 155 context.precision = precision + 2;
156 Decimal HALF = Decimal(0.5);
157 Decimal ONE = Decimal(1);
158 Decimal x = HALF * (arg + ONE);
159 Decimal xp;
160 while(true){
161 xp = x;
162 x = HALF * (x + arg/x);
163 if (x == xp) break;
164 }
165 popContext();
166 round(xp);
167 return xp;
92 } 168 }
93 169
94 //-------------------------------- 170 //--------------------------------
95 // 171 //
96 // EXPONENTIAL AND LOGARITHMIC FUNCTIONS 172 // EXPONENTIAL AND LOGARITHMIC FUNCTIONS
310 Decimal atanh(Decimal arg) { 386 Decimal atanh(Decimal arg) {
311 Decimal result; 387 Decimal result;
312 return result; 388 return result;
313 } 389 }
314 390
315 //-------------------------------- 391 /+ //--------------------------------
316 // 392 //
317 // General Decimal Arithmetic Specification Functions 393 // General Decimal Arithmetic Specification Functions
318 // 394 //
319 //-------------------------------- 395 //--------------------------------
320 396
551 */ 627 */
552 Decimal compareTotal(Decimal op1, Decimal op2) { 628 Decimal compareTotal(Decimal op1, Decimal op2) {
553 Decimal result; 629 Decimal result;
554 return result; 630 return result;
555 } 631 }
556 632 +/
557 633
558 634