[Tutor] numerical problem

[Ben Finney]

Gabriele Brambilla <gb.gabrielebrambilla at gmail.com> writes:

> the values in www are like 1.01e-134 and also smaller, and I sum values
> like this: there could be any problem summing so small numbers?

The default floating-point number type in Python is a fixed-precision
float <URL:http://docs.python.org/3/library/stdtypes.html#typesnumeric>.

Yes, with the ‘float’ type calcuations will lose information, and
calculations at differing orders of magnitude will lose information
faster. That's a limitation of any fixed-precision float implementation.

If you want to use different types with different trade-offs, see
<URL:http://docs.python.org/3/library/stdtypes.html#typesnumeric> the
Python documentation and the NumPy documentation
<URL:http://docs.scipy.org/doc/numpy/user/basics.types.html> for the
numeric data types they support.

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Ben Finney