rsqsim_api.fault.splines
========================

.. py:module:: rsqsim_api.fault.splines

.. autoapi-nested-parse::

   Spline utilities for constructing idealised slip distributions on fault patches.

   Provides functions that build :class:`scipy.interpolate.UnivariateSpline`
   objects encoding along-fault and depth-dependent slip profiles, suitable
   for imposing prescribed slip distributions in RSQSim or other fault models.



Functions
---------

.. autoapisummary::

   rsqsim_api.fault.splines.fault_edge_spline
   rsqsim_api.fault.splines.fault_depth_spline


Module Contents
---------------

.. py:function:: fault_edge_spline(max_slip, distance_width, total_width, min_slip_fraction = 0.0, line_stop_fraction = 0.5, gradient_change = 1.2, spline_k = 3, spline_s = 0.0, resolution = 10.0)

   Build a univariate spline encoding slip as a function of along-fault distance.

   Constructs an interpolated spline that ramps from a minimum slip
   fraction at the fault edge up to the maximum slip, with a
   piecewise-linear interpolant shaped by the supplied parameters.

   :param max_slip: Maximum slip value (m or m/yr) at the centre of the fault.
   :type max_slip: float
   :param distance_width: Along-fault distance (m) at which ``max_slip`` is reached.
   :type distance_width: float
   :param total_width: Total along-fault width (m) of the spline domain.
   :type total_width: float
   :param min_slip_fraction: Fraction of ``max_slip`` at the fault edge (distance = 0).
                             Defaults to 0.
   :type min_slip_fraction: float, optional
   :param line_stop_fraction: Fraction of ``distance_width`` at which the initial ramp
                              levels off before the gradient change.  Defaults to 0.5.
   :type line_stop_fraction: float, optional
   :param gradient_change: Multiplicative factor applied to the intermediate y value to
                           create a smooth overshoot before the final ramp.  Defaults to
                           1.2.
   :type gradient_change: float, optional
   :param spline_k: Degree of the smoothing spline.  Defaults to 3 (cubic).
   :type spline_k: int, optional
   :param spline_s: Smoothing factor passed to
                    :class:`~scipy.interpolate.UnivariateSpline`.  Defaults to
                    0.0 (interpolating spline).
   :type spline_s: float, optional
   :param resolution: Sample spacing (m) used when building the x-axis for
                      interpolation.  Defaults to 10.
   :type resolution: float, optional

   :returns: Spline object; call with an x array (metres from edge) to
             evaluate the slip profile.
   :rtype: scipy.interpolate.UnivariateSpline


.. py:function:: fault_depth_spline(gradient_change_x, after_change_fract, resolution = 0.01, after_change_gradient = 1.2, spline_k = 3, spline_s = 0.0)

   Build a univariate spline encoding normalised slip as a function of normalised depth.

   Produces a spline on [0, 1] (normalised depth fraction) that is
   approximately flat at 1 down to ``gradient_change_x``, then ramps
   linearly to 0 at the base of the fault, with an optional gradient
   overshoot controlled by ``after_change_gradient``.

   :param gradient_change_x: Normalised depth (0–1) at which the gradient begins to change.
   :type gradient_change_x: float
   :param after_change_fract: Fraction of the remaining depth below ``gradient_change_x``
                              over which the gradient change is applied.
   :type after_change_fract: float
   :param resolution: Sample spacing in normalised depth used when building the
                      spline.  Defaults to 0.01.
   :type resolution: float, optional
   :param after_change_gradient: Multiplicative factor that controls the magnitude of the
                                 gradient overshoot.  Defaults to 1.2.
   :type after_change_gradient: float, optional
   :param spline_k: Degree of the smoothing spline.  Defaults to 3 (cubic).
   :type spline_k: int, optional
   :param spline_s: Smoothing factor passed to
                    :class:`~scipy.interpolate.UnivariateSpline`.  Defaults to
                    0.0 (interpolating spline).
   :type spline_s: float, optional

   :returns: Spline object; call with a normalised-depth array to evaluate
             the depth-dependent slip multiplier.
   :rtype: scipy.interpolate.UnivariateSpline