def spreading_pressure(self, pressure):
    '\n        Calculate spreading pressure at specified gas pressure.\n\n        Function that calculates spreading pressure by solving the\n        following integral at each point i.\n\n        .. math::\n\n            \\pi = \\int_{0}^{p_i} \\frac{n_i(p_i)}{p_i} dp_i\n\n        The integral for the TemkinApprox model is solved analytically.\n\n        .. math::\n\n            \\pi = n_m \\Big( \\ln{(1 + K p)} + \\frac{\\theta (2 K p + 1)}{2(1 + K p)^2}\\Big)\n\n        Parameters\n        ----------\n        pressure : float\n            The pressure at which to calculate the spreading pressure.\n\n        Returns\n        -------\n        float\n            Spreading pressure at specified pressure.\n        '
    one_plus_kp = (1.0 + (self.params['K'] * pressure))
    return (self.params['n_m'] * (numpy.log(one_plus_kp) + ((self.params['tht'] * (((2.0 * self.params['K']) * pressure) + 1.0)) / (2.0 * (one_plus_kp ** 2)))))
Calculate spreading pressure at specified gas pressure.

Function that calculates spreading pressure by solving the
following integral at each point i.

.. math::

    \pi = \int_{0}^{p_i} \frac{n_i(p_i)}{p_i} dp_i

The integral for the TemkinApprox model is solved analytically.

.. math::

    \pi = n_m \Big( \ln{(1 + K p)} + \frac{\theta (2 K p + 1)}{2(1 + K p)^2}\Big)

Parameters
----------
pressure : float
    The pressure at which to calculate the spreading pressure.

Returns
-------
float
    Spreading pressure at specified pressure.
def spreading_pressure(self, pressure):
    '\n        Calculate spreading pressure at specified gas pressure.\n\n        Function that calculates spreading pressure by solving the\n        following integral at each point i.\n\n        .. math::\n\n            \\pi = \\int_{0}^{p_i} \\frac{n_i(p_i)}{p_i} dp_i\n\n        The integral for the TemkinApprox model is solved analytically.\n\n        .. math::\n\n            \\pi = n_m \\Big( \\ln{(1 + K p)} + \\frac{\\theta (2 K p + 1)}{2(1 + K p)^2}\\Big)\n\n        Parameters\n        ----------\n        pressure : float\n            The pressure at which to calculate the spreading pressure.\n\n        Returns\n        -------\n        float\n            Spreading pressure at specified pressure.\n        '
    one_plus_kp = (1.0 + (self.params['K'] * pressure))
    return (self.params['n_m'] * (numpy.log(one_plus_kp) + ((self.params['tht'] * (((2.0 * self.params['K']) * pressure) + 1.0)) / (2.0 * (one_plus_kp ** 2)))))