cross_section

mdtools.numpy_helper_functions.cross_section(z, x, y, line, num=None, order=1)[source]

Extract a cross section from a 2-dimensional array along a given line using scipy.ndimage.map_coordinates(). See also https://stackoverflow.com/questions/18920614/plot-cross-section-through-heat-map

Parameters:

  • z (array_like) – Input array of shape (m, n) from which to extract the cross section. The data representation follows the standard matrix convention, i.e. columns represent the x values and rows the y values.

  • x, y (array_like) – The sample points corresponding to the z values. x must be of shape (n,) and y must be of shape (m,).

  • line (array_like) – Start point and end point of the line along which to extract the cross section. line must be given in the following format: [(x0, y0), (x1, y1)] with (x0, y0) being the start point and (x1, y1) being the end point. Note that the start point and end point must lie within the data range given by x and y.

  • num (int, optional) – Number of points to use for sampling the cross section along the given line. If None (default), approximately as many sample points are used as real data points are on the line.

  • order (int, optional) – Interpolation order.

Returns:

  • cs (numpy.ndarray) – (Interpolated) values of z along the given line.

  • r (numpy.ndarray) – The sample points along the given line.