boolean localflag, globalflag=false;
// Test rtsafe
System.out.println("Testing rtsafe");
Funcd_rtsafe fxd = new Funcd_rtsafe();
Zbrak z = new Zbrak(); z.zbrak(fxd,x1,x2,100);
xb1= z.xb1;xb2=z.xb2;nroot = z.nroot;
double[] root = new double[nroot];
for (i=0;i<nroot;i++) {
xacc=0.5*sbeps*(abs(xb1[i])+abs(xb2[i]));
root[i]=rtsafe(fxd,xb1[i],xb2[i],xacc);