How do I print a double value with full precision using cout?

You can set the precision directly on std::cout and use the std::fixed format specifier. double d = 3.14159265358979; cout.precision(17); cout << “Pi: ” << fixed << d << endl; You can #include <limits> to get the maximum precision of a float or double. #include <limits> typedef std::numeric_limits< double > dbl; double d = 3.14159265358979; cout.precision(dbl::max_digits10); … Read more

Why is 24.0000 not equal to 24.0000 in MATLAB?

The problem you’re having relates to how floating-point numbers are represented on a computer. A more detailed discussion of floating-point representations appears towards the end of my answer (The “Floating-point representation” section). The TL;DR version: because computers have finite amounts of memory, numbers can only be represented with finite precision. Thus, the accuracy of floating-point … Read more

Why are floating point numbers inaccurate?

In most programming languages, floating point numbers are represented a lot like scientific notation: with an exponent and a mantissa (also called the significand). A very simple number, say 9.2, is actually this fraction: 5179139571476070 * 2 -49 Where the exponent is -49 and the mantissa is 5179139571476070. The reason it is impossible to represent … Read more

Need a python module for numerical and scientific computing other than NumPy and SciPy

There is nothing unreliable about numpy’s behavior in the examples you show as compared to MATLAB, nor do any of the examples you show have anything to do with floating-point issues (with one exception). For the rounding behavior, MATLAB is the one doing it wrong here. Numpy is following the IEEE standard for rounding. The … Read more