D.7.2 gslint output

In all cases, if no exception occurs, the result returned is an approximation of the integral of f over the interval from a to b or from the first item of p to the last.

Results may differ in numerical properties depending on the integration method and the tolerance used.

• The qagp* and qagx* functions use an adaptive algorithm, whereas the qng* functions use a faster non-adaptive algorithm suitable only for smooth integrands.
• Faster and maybe more accurate results are obtained for discontinuous or non-differentiable integrands by the qagp* integration methods if the interior points in p are chosen to coincide with the discontinuities or corners.
• Larger tolerances are conducive to faster but less accurate results in most cases.