msh_parser

dg_maxwell.msh_parser.plot_element_boundary(x_nodes, y_nodes, axes_handler, grid_width=2.0, grid_color='blue')[source]

Plots the boundary of a given \(2^{nd}\) order element.

Parameters:

x_nodes : np.ndarray [8]

\(x\) nodes of the element.

y_nodes : np.ndarray [8]

\(y\) nodes of the element.

axes_handler : matplotlib.axes.Axes

The plot handler being used to plot the element grid. You may generate it by calling the function pyplot.axes()

grid_width : float

Grid line width.

grid_color : str

Grid line color.
Returns:

None
dg_maxwell.msh_parser.plot_element_grid(x_nodes, y_nodes, xi_LGL, eta_LGL, axes_handler, grid_width=1.0, grid_color='red')[source]

Uses the \(\xi_{LGL}\) and \(\eta_{LGL}\) points to plot a grid in the \(x-y\) plane using the points corresponding to the \((\xi_{LGL}, \eta_{LGL})\) points.

Usage

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# Plots a grid for an element using 8 LGL points

N_LGL        = 8
xi_LGL       = lagrange.LGL_points(N)
eta_LGL      = lagrange.LGL_points(N)

# 8 x_nodes and y_nodes of an element
x_nodes = [0., 0., 0., 0.5, 1., 1., 1., 0.5]
y_nodes = [1., 0.5, 0., 0., 0., 0.5,  1., 1.]

axes_handler = pyplot.axes()
msh_parser.plot_element_grid(x_nodes, y_nodes,
                             xi_LGL, eta_LGL, axes_handler)

pyplot.title(r'Gird plot of an element.')
pyplot.xlabel(r'$x$')
pyplot.ylabel(r'$y$')

pyplot.xlim(-.1, 1.1)
pyplot.ylim(-.1, 1.1)

pyplot.show()
Parameters:

x_nodes : np.array [8]

x_nodes of the element.

y_nodes : np.array [8]

y_nodes of the element.

xi_LGL : np.array [N_LGL]

LGL points on the \(\xi\) axis

eta_LGL : np.array [N_LGL]

LGL points on the \(\eta\) axis

axes_handler : matplotlib.axes.Axes

The plot handler being used to plot the element grid. You may generate it by calling the function pyplot.axes()

grid_width : float

Grid line width.

grid_color : str

Grid line color.
Returns:

None
dg_maxwell.msh_parser.plot_mesh_grid(nodes, elements, xi_LGL, eta_LGL, axes_handler)[source]

Plots the mesh grid.

Parameters:

nodes : np.ndarray [N, 2]

Array of nodes in the mesh. First column and the second column are the \(x\) and \(y\) coordinates respectivily.

elements : np.ndarray [N_e, 8]

Array of elements.

xi_LGL : np.array [N_LGL]

LGL points on the \(\xi\) axis

eta_LGL : np.array [N_LGL]

LGL points on the \(\eta\) axis

axes_handler : matplotlib.axes.Axes

The plot handler being used to plot the element grid. You may generate it by calling the function pyplot.axes()
Returns:

None
dg_maxwell.msh_parser.read_order_2_msh(msh_file)[source]

Parses the \(2^{nd}\) order .msh files.

Parameters:

msh_file : str

.msh file to be parsed
Returns:

tuple(np.ndarray, np.ndarray)

Tuple of Nodes and Elements respectively. Nodes is a \(N \times 2\) array, where, \(N\) is the total number of Nodes in the mesh. Each node contains it’s \((x, y)\) coordinates. Elements is a \(N_e \times 8\) array which contains the tags of all the nodes which defines each element. A tag of a node is the array index of a node.