19.7 Minimizing Roundoff Error

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There are many techniques for minimizing roundoff error. Guard digits have already been discussed. Another trick is to use double instead of float . This gives you approximately twice the accuracy as well as twice the range. It also pushes away the minimization problem twice as far. But roundoff errors still can creep in.

Advanced techniques for limiting the problems caused by floating point can be found in books on numerical analysis. They are beyond the scope of this text. The purpose of this chapter is to give you some idea of what sort of problems can be encountered .

Floating point by its very nature is not exact. People tend to think of computers as very accurate machines. They can be, but they also can give wildly wrong results. You should be aware of the places where errors can slip into your program.

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