/* AQ.H
xref:
input:
output: stdout
does    - Globally adaptive quadrature - Header file
does    - Globally adaptive quadrature
        - Kronrod 7-point rule (Gauss-Legendre n=3).
        - univariate integration over finite intervals
*/
/************************************************************/

double AdaptQuad (double f(double), double a, double b,
              double abserr,
              double relerr,
              double maxneval,
              int*   rc,
              int*   neval,
              double* ehat);
/*

Globally adaptive quadrature over a finite interval
Uses a 7-point Gauss-Legendre-Kronrod as the basic building block.
Input:
f       = function to be integrated
a, b    = limits of integration, a < b works properly
abserr  = absolute error tolerance
relerr  = relative error tolerance
maxneval= max acceptable # of function evaluations f(x)
Output:
returns value of integral,
*rc     <- 1 if converged, 0 otherwise,
*neval  <- # function evaluations
*ehat   <- error estimate (error := true - estimate)

*/