Module « numpy.matlib »

Fonction format_float_scientific - module numpy.matlib

Signature de la fonction format_float_scientific

def format_float_scientific(x, precision=None, unique=True, trim='k', sign=False, pad_left=None, exp_digits=None) 

Description

format_float_scientific.__doc__

    Format a floating-point scalar as a decimal string in scientific notation.

    Provides control over rounding, trimming and padding. Uses and assumes
    IEEE unbiased rounding. Uses the "Dragon4" algorithm.

    Parameters
    ----------
    x : python float or numpy floating scalar
        Value to format.
    precision : non-negative integer or None, optional
        Maximum number of digits to print. May be None if `unique` is
        `True`, but must be an integer if unique is `False`.
    unique : boolean, optional
        If `True`, use a digit-generation strategy which gives the shortest
        representation which uniquely identifies the floating-point number from
        other values of the same type, by judicious rounding. If `precision`
        was omitted, print all necessary digits, otherwise digit generation is
        cut off after `precision` digits and the remaining value is rounded.
        If `False`, digits are generated as if printing an infinite-precision
        value and stopping after `precision` digits, rounding the remaining
        value.
    trim : one of 'k', '.', '0', '-', optional
        Controls post-processing trimming of trailing digits, as follows:

        * 'k' : keep trailing zeros, keep decimal point (no trimming)
        * '.' : trim all trailing zeros, leave decimal point
        * '0' : trim all but the zero before the decimal point. Insert the
          zero if it is missing.
        * '-' : trim trailing zeros and any trailing decimal point
    sign : boolean, optional
        Whether to show the sign for positive values.
    pad_left : non-negative integer, optional
        Pad the left side of the string with whitespace until at least that
        many characters are to the left of the decimal point.
    exp_digits : non-negative integer, optional
        Pad the exponent with zeros until it contains at least this many digits.
        If omitted, the exponent will be at least 2 digits.

    Returns
    -------
    rep : string
        The string representation of the floating point value

    See Also
    --------
    format_float_positional

    Examples
    --------
    >>> np.format_float_scientific(np.float32(np.pi))
    '3.1415927e+00'
    >>> s = np.float32(1.23e24)
    >>> np.format_float_scientific(s, unique=False, precision=15)
    '1.230000071797338e+24'
    >>> np.format_float_scientific(s, exp_digits=4)
    '1.23e+0024'