Implementation and Evaluation of Interval Arithmetic Software. Report 5. The CDC CYBER 70 System.

摘要

This is Report 5 of a series entitled 'Implementation and Evaluation of Interval Arithmetic Software. 'The potential user of this or any other interval analysis package should take into consideration the limitations of this technique. Some of the limitations are inherent in all interval analysis implementations and others are dependent upon one specific package. The user should be aware that software interval analysis tends to be very slow; cases run on one CDC CYBER 70 have required as much 100-fold increase in execution time over a noninterval version. Thus, large production codes involving significant amounts of floating-point computations are not viable candidates for a complete interval implementation; however, small portions of the computation might benefit from use of the package. The computed bounds using interval analysis can be overly pessimistic as well as being time-consuming to determine. The tightness of the bounds is dependent upon the arithmetic of the host computer and possible numerical anomalies introduced by compile-time arithmetic. Another factor affecting the performance of the interval package is the accuracy of the host computer's FORTRAN library routines.