flopy.discretization.structuredgrid module

class StructuredGrid(delc=None, delr=None, top=None, botm=None, idomain=None, lenuni=None, crs=None, epsg=None, proj4=None, prj=None, prjfile=None, xoff=0.0, yoff=0.0, angrot=0.0, nlay=None, nrow=None, ncol=None, laycbd=None)[source]

Bases: Grid

class for a structured model grid

Parameters:

  • delr (float or ndarray) – column spacing along a row.

  • delc (float or ndarray) – row spacing along a column.

  • top (float or ndarray) – top elevations of cells in topmost layer

  • botm (float or ndarray) – bottom elevations of all cells

  • idomain (int or ndarray) – ibound/idomain value for each cell

  • lenuni (int or ndarray) – model length units

  • crs (pyproj.CRS, optional if prjfile is specified) – Coordinate reference system (CRS) for the model grid (must be projected; geographic CRS are not supported). The value can be anything accepted by pyproj.CRS.from_user_input(), such as an authority string (eg “EPSG:26916”) or a WKT string.

  • prjfile (str or pathlike, optional if crs is specified) – ESRI-style projection file with well-known text defining the CRS for the model grid (must be projected; geographic CRS are not supported).

  • xoff (float) – x coordinate of the origin point (lower left corner of model grid) in the spatial reference coordinate system

  • yoff (float) – y coordinate of the origin point (lower left corner of model grid) in the spatial reference coordinate system

  • angrot (float) – rotation angle of model grid, as it is rotated around the origin point

  • Properties –

  • ---------- –

  • nlay – returns the number of model layers

  • nrow – returns the number of model rows

  • ncol – returns the number of model columns

  • delc – returns the delc array

  • delr – returns the delr array

  • xyedges – returns x-location points for the edges of the model grid and y-location points for the edges of the model grid

get_cell_vertices(i, j)[source]

returns vertices for a single cell at row, column i, j.

array_at_faces(a, direction, withnan=True)[source]

Computes values at the center of cell faces using linear interpolation.

Parameters:

  • a (ndarray) – Values at cell centers, shape (nlay, row, ncol).

  • direction (str, possible values are 'x', 'y' and 'z') – Direction in which values will be interpolated at cell faces.

  • withnan (bool) – If True (default), the result value will be set to NaN where the cell face sits between inactive cells. If False, not.

Returns:

afaces – Array values interpolated at cell vertices, shape as input extended by 1 along the specified direction.

Return type:

ndarray

array_at_verts(a)[source]

Interpolate array values at cell vertices.

Parameters:

a (ndarray) – Array values. Allowed shapes are: (nlay, nrow, ncol), (nlay, nrow, ncol+1), (nlay, nrow+1, ncol) and (nlay+1, nrow, ncol). * When the shape is (nlay, nrow, ncol), input values are considered at cell centers, and output values are computed by trilinear interpolation. * When the shape is extended in one direction, input values are considered at the center of cell faces in this direction, and output values are computed by bilinear interpolation in planes defined by these cell faces.

Returns:

averts – Array values interpolated at cell vertices, shape (nlay+1, nrow+1, ncol+1).

Return type:

ndarray

Notes

  • Output values are smooth (continuous) even if top elevations or

bottom elevations are not constant across layers (i.e., in this case, vertices of neighboring cells are implicitly merged). * NaN values are assigned in accordance with inactive cells defined by idomain.

array_at_verts_basic(a)[source]

Computes values at cell vertices using neighbor averaging.

Parameters:

a (ndarray) – Array values at cell centers.

Returns:

averts – Array values at cell vertices, shape (a.shape[0]+1, a.shape[1]+1, a.shape[2]+1). NaN values are assigned in accordance with inactive cells defined by idomain.

Return type:

ndarray

property cross_section_vertices

Get a set of xvertices and yvertices ordered by node for plotting cross sections

Returns:

xverts, yverts

Return type:

(np.ndarray, np.ndarray)

property delc
property delr
property delz
property extent
classmethod from_binary_grid_file(file_path, verbose=False)[source]

Instantiate a StructuredGrid model grid from a MODFLOW 6 binary grid (*.grb) file.

Parameters:

  • file_path (str) – file path for the MODFLOW 6 binary grid file

  • verbose (bool) – Write information to standard output. Default is False.

Returns:

return

Return type:

StructuredGrid

classmethod from_gridspec(file_path: str | PathLike, lenuni=0)[source]

Instantiate a StructuredGrid from grid specification file.

Parameters:

  • file_path (str or PathLike) – Path to the grid specification file

  • lenuni (int) – Length unit code

Return type:

A StructuredGrid

get_cell_vertices(*args, **kwargs)[source]
Method to get a set of cell vertices for a single cell

used in the Shapefile export utilities and plotting code

Parameters:

  • node – (int) node number

  • i – (int) cell row number

  • j – (int) cell column number

Returns ——- list of x,y cell vertices

get_lrc(nodes)[source]

Get layer, row, column from a list of zero-based MODFLOW node numbers.

Parameters:

nodes (int, list or array_like) – Zero-based node number

Returns:

list of tuples containing the layer (k), row (i), and column (j) for each node in the input list

Return type:

list

Examples

>>> import flopy
>>> sg = flopy.discretization.StructuredGrid(nlay=20, nrow=30, ncol=40)
>>> sg.get_lrc(100)
[(0, 2, 20)]
>>> sg.get_lrc([100, 1000, 10_000])
[(0, 2, 20), (0, 25, 0), (8, 10, 0)]
get_node(lrc_list)[source]

Get node number from a list of zero-based MODFLOW layer, row, column tuples.

Parameters:

lrc_list (tuple of int or list of tuple of int) – Zero-based layer, row, column tuples

Returns:

list of MODFLOW nodes for each layer (k), row (i), and column (j) tuple in the input list

Return type:

list

Examples

>>> import flopy
>>> sg = flopy.discretization.StructuredGrid(nlay=20, nrow=30, ncol=40)
>>> sg.get_node((0, 2, 20))
[100]
>>> sg.get_node([(0, 2, 20), (0, 25, 0), (8, 10, 0)])
[100, 1000, 10000]
get_number_plottable_layers(a)[source]

Calculate and return the number of 2d plottable arrays that can be obtained from the array passed (a)

Parameters:

a (ndarray) – array to check for plottable layers

Returns:

nplottable – number of plottable layers

Return type:

int

get_plottable_layer_array(a, layer)[source]
property grid_lines

Get the grid lines as a list

intersect(x, y, z=None, local=False, forgive=False)[source]

Get the row and column of a point with coordinates x and y

When the point is on the edge of two cells, the cell with the lowest row or column is returned.

Parameters:

  • x (float) – The x-coordinate of the requested point

  • y (float) – The y-coordinate of the requested point

  • z (float) – Optional z-coordinate of the requested point (will return layer, row, column) if supplied

  • local (bool (optional)) – If True, x and y are in local coordinates (defaults to False)

  • forgive (bool (optional)) – Forgive x,y arguments that fall outside the model grid and return NaNs instead (defaults to False - will throw exception)

Returns:

  • row (int) – The row number

  • col (int) – The column number

property is_complete
property is_rectilinear

Test whether the grid is rectilinear (it is always so in the x and y directions, but not necessarily in the z direction).

property is_regular

Test if the grid spacing is regular and equal in x, y and z directions.

property is_regular_x

Test whether the grid spacing is regular in the x direction.

property is_regular_xy

Test if the grid spacing is regular and equal in x and y directions.

property is_regular_xz

Test if the grid spacing is regular and equal in x and z directions.

property is_regular_y

Test whether the grid spacing is regular in the y direction.

property is_regular_yz

Test if the grid spacing is regular and equal in y and z directions.

property is_regular_z

Test if the grid spacing is regular in z direction.

property is_valid
property iverts
property map_polygons

Get a list of matplotlib Polygon patches for plotting

Return type:

list of Polygon objects

property ncol
property ncpl
neighbors(*args, **kwargs)[source]

Method to get nearest neighbors for a cell

Parameters:

  • *args – lay (int), row (int), column (int) or node (int)

  • **kwargs –

    kint

    layer number

    iint

    row number

    jint

    column number

    as_nodebool

    flag to return neighbors as node numbers

Return type:

list of neighboring cells

property nlay
property nnodes
property nrow
property nvert
plot(**kwargs)[source]

Plot the grid lines.

Parameters:

kwargs (ax, colors. The remaining kwargs are passed into the) – the LineCollection constructor.

Returns:

lc

Return type:

matplotlib.collections.LineCollection

property shape
property top_botm
property top_botm_withnan

Same as top_botm array but with NaN where idomain==0 both above and below a cell.

property verts
property xycenters

Return a list of two numpy one-dimensional float arrays for center x and y coordinates in model space - not offset or rotated.

property xyedges

one with the cell edge x coordinate (size = ncol+1) and the other with the cell edge y coordinate (size = nrow+1) in model space - not offset or rotated.

Type:

Return a list of two 1D numpy arrays

property xyzcellcenters

two two-dimensional arrays for center x and y coordinates, and one three-dimensional array for center z coordinates. Coordinates are given in real-world coordinates.

Type:

Return a list of three numpy float arrays

property xyzvertices

Method to get all grid vertices in a layer

Returns:

[] 2D array

property zedges

Return zedges for (column, row)==(0, 0).

property zverts_smooth

Get a unique z of cell vertices using bilinear interpolation of top and bottom elevation layers.

Returns:

zverts – z of cell vertices. NaN values are assigned in accordance with inactive cells defined by idomain.

Return type:

ndarray, shape (nlay+1, nrow+1, ncol+1)

array_at_faces_1d(a, delta)[source]

Interpolate array at cell faces of a 1d grid using linear interpolation.

Parameters:

  • a (1d ndarray) – Values at cell centers.

  • delta (1d ndarray) – Grid steps.

Returns:

afaces – Array values interpolated at cell faces, shape as input extended by 1.

Return type:

1d ndarray

array_at_verts_basic2d(a)[source]

Computes values at cell vertices on 2d array using neighbor averaging.

Parameters:

a (ndarray) – Array values at cell centers, could be a slice in any orientation.

Returns:

averts – Array values at cell vertices, shape (a.shape[0]+1, a.shape[1]+1).

Return type:

ndarray