double MyParser::EvalRemoveSingularity(double *xvar)
{
try {
double result = Eval();
if ( gsl_isinf(result) || gsl_isnan(result) )
throw Singularity();
return result;
} catch (Singularity) {
try {
if (isinf(Eval()))
throw Pole();
int n;
frexp (*xvar, &n);
double xp = *xvar + ldexp(DBL_EPSILON,n);
double xm = *xvar - ldexp(DBL_EPSILON,n);
*xvar = xp;
double yp = Eval();
if (gsl_isinf(yp) || gsl_isnan(yp))
throw Pole();
*xvar = xm;
double ym = Eval();
if (gsl_isinf(ym) || gsl_isnan(ym))
throw Pole();
return (yp + ym)/2;
} catch (Pole) {
SingularityErrorMessage(*xvar);
return GSL_ESING;
}
}
}
globle double CscFunction(
void *theEnv)
{
double num, tv;
if (SingleNumberCheck(theEnv,"csc",&num) == FALSE) return(0.0);
tv = sin(num);
if ((tv < SMALLEST_ALLOWED_NUMBER) && (tv > -SMALLEST_ALLOWED_NUMBER))
{
SingularityErrorMessage(theEnv,"csc");
return(0.0);
}
return(1.0 / tv);
}
globle double CothFunction(
void *theEnv)
{
double num;
if (SingleNumberCheck(theEnv,"coth",&num) == FALSE) return(0.0);
if (num == 0.0)
{
SingularityErrorMessage(theEnv,"coth");
return(0.0);
}
else if (TestProximity(num,1e-25) == TRUE)
{
ArgumentOverflowErrorMessage(theEnv,"coth");
return(0.0);
}
return(1.0 / tanh(num));
}