import java.math.BigDecimal;
import java.math.MathContext;
import java.math.RoundingMode; /**
* 科学计算数字的帮助类
* @author yzl
*
*/
public class MathUtils {
/**
* 返回科学计算后的乘法结果
* @param val1
* @param val2
* @param mc 精度
* @param more 更多
* @return
*/
public static double multiply(double val1,double val2,int mc,double... more) {
if(val1==0 || val2==0) return 0;
BigDecimal bg1 = new BigDecimal(val1);
BigDecimal bg2 = new BigDecimal(val2);
BigDecimal result = new BigDecimal(0); if(more.length>0){
for(int i=0,len=more.length; i<len; i++){
if(i<len-1){
result = result.multiply(new BigDecimal(more[i]));
}else{
result = result.multiply(new BigDecimal(more[i]), new MathContext(mc,RoundingMode.HALF_UP));
}
}
}else{
result = bg1.multiply(bg2, new MathContext(mc,RoundingMode.HALF_UP));
} return result.doubleValue();
}
/**
* 返回科学计算后的除法结果
* @param fz 分子
* @param fm 分母
* @param mc 精度
* @param more 更多
* @return
*/
public static double divide(double fz,double fm,int mc,double... more) {
if(fz==0 || fm==0) return 0;
BigDecimal bg1 = new BigDecimal(fz);
BigDecimal bg2 = new BigDecimal(fm);
BigDecimal result = new BigDecimal(0); if(more.length>0){
for(int i=0,len=more.length; i<len; i++){
if(i<len-1){
result = result.divide(new BigDecimal(more[i]));
}else{
result = result.divide(new BigDecimal(more[i]), new MathContext(mc,RoundingMode.HALF_UP));
}
}
}else{
result = bg1.divide(bg2, new MathContext(mc,RoundingMode.HALF_UP));
} return result.doubleValue();
} /**
* 返回科学计算后的减法结果
* @param val1
* @param val2
* @param mc 精度
* @param more 更多
* @return
*/
public static double subtract(double val1,double val2,int mc,double... more) {
if(val2==0) return val1;
BigDecimal bg1 = new BigDecimal(val1);
BigDecimal bg2 = new BigDecimal(val2);
BigDecimal result = new BigDecimal(0); if(more.length>0){
for(int i=0,len=more.length; i<len; i++){
if(i<len-1){
result = result.subtract(new BigDecimal(more[i]));
}else{
result = result.subtract(new BigDecimal(more[i]), new MathContext(mc,RoundingMode.HALF_UP));
}
}
}else{
result = bg1.subtract(bg2, new MathContext(mc,RoundingMode.HALF_UP));
} return result.doubleValue();
} /**
* 返回科学计算后的加法结果
* @param val1
* @param val2
* @param mc 精度
* @param more 更多
* @return
*/
public static double add(double val1,double val2,int mc,double... more) {
BigDecimal bg1 = new BigDecimal(val1);
BigDecimal bg2 = new BigDecimal(val2);
BigDecimal result = new BigDecimal(0); if(more.length>0){
for(int i=0,len=more.length; i<len; i++){
if(i<len-1){
result = result.add(new BigDecimal(more[i]));
}else{
result = result.add(new BigDecimal(more[i]), new MathContext(mc,RoundingMode.HALF_UP));
}
}
}else{
result = bg1.add(bg2, new MathContext(mc,RoundingMode.HALF_UP));
} return result.doubleValue();
}
}