mirror of https://github.com/python/cpython.git
60 lines
1.6 KiB
TeX
60 lines
1.6 KiB
TeX
\section{Built-in Module \sectcode{cmath}}
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\label{module-cmath}
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\bimodindex{cmath}
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\renewcommand{\indexsubitem}{(in module cmath)}
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This module is always available.
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It provides access to mathematical functions for complex numbers.
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The functions are:
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\iftexi
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\begin{funcdesc}{acos}{x}
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\funcline{asin}{x}
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\funcline{atan}{x}
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\funcline{cos}{x}
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\funcline{cosh}{x}
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\funcline{exp}{x}
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\funcline{log}{x}
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\funcline{log10}{x}
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\funcline{sin}{x}
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\funcline{sinh}{x}
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\funcline{sqrt}{x}
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\funcline{tan}{x}
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\funcline{tanh}{x}
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\end{funcdesc}
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\else
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\code{acos(\varvars{x})},
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\code{acosh(\varvars{x})},
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\code{asin(\varvars{x})},
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\code{asinh(\varvars{x})},
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\code{atan(\varvars{x})},
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\code{atanh(\varvars{x})},
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\code{cos(\varvars{x})},
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\code{cosh(\varvars{x})},
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\code{exp(\varvars{x})},
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\code{log(\varvars{x})},
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\code{log10(\varvars{x})},
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\code{sin(\varvars{x})},
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\code{sinh(\varvars{x})},
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\code{sqrt(\varvars{x})},
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\code{tan(\varvars{x})},
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\code{tanh(\varvars{x})}.
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\fi
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The module also defines two mathematical constants:
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\iftexi
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\begin{datadesc}{pi}
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\dataline{e}
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\end{datadesc}
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\else
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\code{pi} and \code{e}.
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\fi
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Note that the selection of functions is similar, but not identical, to
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that in module \code{math}. The reason for having two modules is,
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that some users aren't interested in complex numbers, and perhaps
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don't even know what they are. They would rather have \code{math.sqrt(-1)}
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raise an exception than return a complex number. Also note that the
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functions defined in \code{cmath} always return a complex number, even
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if the answer can be expressed as a real number (in which case the
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complex number has an imaginary part of zero).
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