loadcartesianfields.py

jcmwave.loadcartesianfields(file_name, format='squeeze')

Loads a tensor fields given on a Cartesian grid stored in .jcm format.

Parameters:
  • file_name (filepath) – path to a Cartesian fieldbag in .jcm format.
  • format (str) –

    format of the table after load.

    Allowed values are: ‘squeeze’ (default) and ‘full’. For details the “Results”.
Returns:

Dictionary with the following entries:

  • ’X’, ‘Y’, ‘Z’ (numpy arrays):

    x, y, z-coordinates of the Cartesian grid. Each X, Y, Z has the shape [nx, ny, nz], where nx, ny, nz are the number of grid points in each direction. X[ix, iy, iz] is the value of sampling vector in x-direction at position ix, 0<=ix<nx, irrespective of iy, iz. Accordingly, we have Y[ix, iy, iz]=y[iy] and Z[ix, iy, iz]=z[iz]. For a Cartesian field in polar coordinates, XYZ arrays are changed to R, Theta and Phi holding the corresponding coordinate values.

  • ’field’ (list of numpy arrays):

    Fj=['field'][j] contains the field values of the (j+1)’th field of the fieldbag. Fj[ix, iy, iz, k] gives the k’th field component at the point with coordinates [x(ix), y(iy), z(iz)] of the (j+1)’th field.

    When ‘format’ is ‘squeeze’, singleton dimensions are removed accordingly to the commands
    >>> X = X.squeeze() 
>>> Y = Y.squeeze() 
>>> Z = Z.squeeze() 
>>> Fj = Fj.squeeze()

Example:

Plot Cartesian fieldbag on xy-mesh. Real part of the z-component of the first
field is plotted. (matplotlib required):

>>> cfb = jcmwave.loadcartesianfields('./project_results/cartesian_xy.jcm');
>>> pcolormesh(cfb['X'], cfb['Y'], cfb['field'][0][:, :, 2].real, shading='gouraud')