/*  sxfbsins.cpp  by K.Tsuru  */
// function ID 5204     BRADIX
#ifndef SN_H
#include "sn.h"
#endif
/**************
SDecimal class
sin x by series
***************/
SDecimal BsinSeries(const SDouble& x){
    SDecimal dx;
    dx = dx.ConvToBin(x);   // radix conversion
    SDecimal sum(dx), xsq, delta;
    ulong n = 4, den, mt = sum.SlOpMaxValue();

    xsq = dx*dx;
    XsDiv(xsq, 6, delta);
    delta *= dx;
    XXSub(sum, delta, sum);

    while(delta.Sign()){
        den = n*(n+1);
        if(den >= mt)   break;
        delta *= xsq;   // DDMult() is used.

        XsDiv(delta, den, delta);
        if(n & 2) XXSub(sum, delta, sum);
        else      XXAdd(sum, delta, sum);
        n += 2;
    }

    while(delta.Sign()){
        if(n >= mt){
            sum.SetError(sum.NOT_CONVERGE,"BsinSeries", -5204);
            break;
        }
        delta *= xsq;
        XsDiv(delta, n, delta);
        XsDiv(delta, n+1, delta);
        if(n & 2) XXSub(sum, delta, sum);
        else      XXAdd(sum, delta, sum);
        n += 2;
    }
    sum.upToTerm = n/2;
    return sum;
}