DanilaFe/Abacus
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Rewrite precise number to limit significant figures rather than decimal places. Add getMaxError to NumberInterface; modify numbers and StandardPlugin appropriately.

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This commit is contained in:
Arthur Drobot
2017-08-07 17:58:18 -07:00
parent 7ae59afade
commit 7b7f9936e4
4 changed files with 40 additions and 20 deletions
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20
src/main/java/org/nwapw/abacus/plugin/StandardPlugin.java
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@@ -188,7 +188,7 @@ public class StandardPlugin extends Plugin {
*/
private NumberInterface getLogPartialSum(NumberInterface x) {
NumberInterface maxError = getMaxError(x);
NumberInterface maxError = x.getMaxError();
x = x.subtract(NaiveNumber.ONE.promoteTo(x.getClass())); //Terms used are for log(x+1).
NumberInterface currentNumerator = x, currentTerm = x, sum = x;
int n = 1;
@@ -207,7 +207,7 @@ public class StandardPlugin extends Plugin {
* @return the value of log(2) with the appropriate precision.
*/
private NumberInterface getLog2(NumberInterface number) {
NumberInterface maxError = getMaxError(number);
NumberInterface maxError = number.getMaxError();
//NumberInterface errorBound = fromInt(number.getClass(), 1);
//We'll use the series \sigma_{n >= 1) ((1/3^n + 1/4^n) * 1/n)
//In the following, a=1/3^n, b=1/4^n, c = 1/n.
@@ -301,7 +301,7 @@ public class StandardPlugin extends Plugin {
@Override
protected NumberInterface applyInternal(NumberInterface[] params) {
NumberInterface maxError = getMaxError(params[0]);
NumberInterface maxError = params[0].getMaxError();
int n = 0;
if (params[0].signum() <= 0) {
NumberInterface currentTerm = NaiveNumber.ONE.promoteTo(params[0].getClass()), sum = currentTerm;
@@ -352,7 +352,7 @@ public class StandardPlugin extends Plugin {
return NaiveNumber.ONE.promoteTo(params[1].getClass());
//Detect integer bases:
if(params[0].fractionalPart().compareTo(fromInt(params[0].getClass(), 0)) == 0
&& FUNCTION_ABS.apply(params[0]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
&& FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[0].getClass(), Integer.MAX_VALUE)) < 0
&& FUNCTION_ABS.apply(params[1]).compareTo(fromInt(params[1].getClass(), 1)) >= 0){
NumberInterface[] newParams = {params[0], params[1].fractionalPart()};
return params[0].intPow(params[1].floor().intValue()).multiply(applyInternal(newParams));
@@ -476,16 +476,6 @@ public class StandardPlugin extends Plugin {
return sum;
}
/**
* Returns the maximum error based on the precision of the class of number.
*
* @param number Any instance of the NumberInterface in question (should return an appropriate precision).
* @return the maximum error.
*/
private static NumberInterface getMaxError(NumberInterface number) {
return fromInt(number.getClass(), 10).intPow(-number.getMaxPrecision());
}
/**
* A factorial function that uses memoization for each number class; it efficiently
* computes factorials of non-negative integers.
@@ -517,7 +507,7 @@ public class StandardPlugin extends Plugin {
*/
private static NumberInterface sinTaylor(NumberInterface x) {
NumberInterface power = x, multiplier = x.multiply(x).negate(), currentTerm = x, sum = x;
NumberInterface maxError = getMaxError(x);
NumberInterface maxError = x.getMaxError();
int n = 1;
do {
n += 2;