Flowmeshreader api-doc#

load_mesh#

flowmeshreader.load_mesh(input_file_path: str) → Tuple[numpy.ndarray, numpy.ndarray][source]#

Retrieves the mesh nodes faces’ x and y-coordinates from the netCDF file at input_file_path

Parameters

input_file_path (str) – path to the input file

Returns

  • node_x (np.ndarray) – x-coordinates of the mesh nodes faces

  • node_y (np.ndarray) – y-coordinates of the mesh nodes faces

load_meta_data#

flowmeshreader.load_meta_data(input_file_path) → List[source]#

Retrieves the svariables from the netCDF file at input_file_path

Parameters

input_file_path (str) – path to the input file

Returns

List – list of variables that can be read.

load_data#

flowmeshreader.load_data(input_file_path: str, variable: str) → numpy.ndarray[source]#

Retrieves the selected mesh data (i.e. variable) from the netCDF file at input_file_path

Parameters

  • input_file_path (str) – path to the input file

  • variable (str) – variable to return

Returns

data (np.ndarray) – data at the mesh nodes

load_fou_data#

flowmeshreader.load_fou_data(input_file_path: str, variable: str) → numpy.ndarray[source]#

Retrieves the selected mesh data (i.e. variable) from the netCDF file at input_file_path

Parameters

  • input_file_path (str) – path to the input file

  • variable (str) – variable to return

Returns

data (np.ndarray) – data at the mesh nodes

load_map_data#

flowmeshreader.load_map_data(input_file_path: str, variable: str) → numpy.ndarray[source]#

Retrieves the selected mesh data (i.e. variable) from the netCDF file at input_file_path. Also restores original dimensions

Parameters

  • input_file_path (str) – path to the input file

  • variable (str) – variable to return

Returns

map_data (np.ndarray) – data at the mesh nodes (time, spatial)

load_classmap_data#

flowmeshreader.load_classmap_data(input_file_path: str, variable: str, method: str = 'average', ret_map_data=True) → Tuple[numpy.ndarray, numpy.ndarray][source]#

Retrieves the selected mesh data (i.e. variable) from the .clm netCDF file at input_file_path Returns (1) the raw data (clm_data) at mesh locations and (2) the filled data (map_data), using class definitions Optional: provide method for replacing class numbers with bin values (lower bound, upper bound, average). Default is average

Parameters

  • input_file_path (str) – path to the input file

  • variable (str) – variable to return

  • method (str) – method to use when replacing classes with values. “lower” replaces class numbers with lower bound; “upper” replaces class numbers with upper bound; “average” replaces class numbers with average of upper and lower bounds. Regardless, the lass class will take the lower bound as it goes to infinity

Returns

  • clm_data (np.ndarray) – classmap data at the mesh nodes (time, spatial)

  • map_data (np.ndarray) – filled classmap data at the mesh nodes, using class definition (time, spatial)

create_raster#

flowmeshreader.create_raster(node_x: numpy.ndarray, node_y: numpy.ndarray, resolution: float, margin: float = 1.05) → Tuple[numpy.ndarray, numpy.ndarray, numpy.ndarray][source]#

Creates a raster that spans from min(node_x) to max(node_x) and from min(node_y) to max(node_y) with user defined resolution

Parameters

  • node_x (np.ndarray) – x-coordinates of the mesh nodes

  • node_y (np.ndarray) – y-coordinates of the mesh nodes

  • resolution (float) – resolution of the raster

  • margin (float) – margin around the node face center that the raster covers, in percentage. A value of 1 corresponds to 100%, the default value of 1.05 corresponds to 105% of the extend of the nodes face coordinates

Returns

  • grid_x (np.ndarray) – x-coordinates of the raster points

  • grid_y (np.ndarray) – y-coordinates of the raster points

  • bounds (np.ndarray) – outermost coordinates of the raster (west, east, south, north)

get_bounds#

flowmeshreader.get_bounds(node_x: numpy.ndarray, node_y: numpy.ndarray, resolution: float, margin: float) → numpy.ndarray[source]#

Determines the raster bounds based on given resolution and margin. Guarantees that the resolution is maintained and extends span if the span in a direction is not an exact multiple of resolution.

Parameters

  • node_x (np.ndarray) – x-coordinates of the mesh nodes

  • node_y (np.ndarray) – y-coordinates of the mesh nodes

  • resolution (float) – resolution of the raster

  • margin (float) – margin around the node face center that the raster covers, in percentage. A value of 1 corresponds to 100%, the default value of 1.05 corresponds to 105% of the extend of the nodes face coordinates

Returns

  • bounds (np.ndarray) – outermost coordinates of the raster (west, east, south, north)

  • n_cells (np.ndarray) – number of cells in x and y direction (x, y)

mesh_data_to_raster#

flowmeshreader.mesh_data_to_raster(node_x: numpy.ndarray, node_y: numpy.ndarray, node_data: numpy.ndarray, grid_x: numpy.ndarray, grid_y: numpy.ndarray, interpolation: str = 'nearest', distance_tol: float = - 999) → numpy.ndarray[source]#

  1. Maps the data at the mesh nodes to the raster points. see e.g. https://hatarilabs.com/ih-en/how-to-create-a-geospatial-raster-from-xy-data-with-python-pandas-and-rasterio-tutorial

  2. Sets raster points to NaN if further away than distance_tol from a mesh node. This allows ‘holes’ in grids and other funky shapes to exist in the raster. Otherwise the convex hull of the mesh is interpolated, resulting in potentially unwanted results.

Parameters

  • node_x (np.ndarray) – x-coordinates of the mesh nodes

  • node_y (np.ndarray) – y-coordinates of the mesh nodes

  • node_data (np.ndarray) – data at the mesh nodes

  • grid_x (np.ndarray) – x-coordinates of the raster points

  • grid_y (np.ndarray) – y-coordinates of the raster points

  • interpolation (str) – interpolation method for scipy.spatial.griddata. (1. “linear”, 2. “nearest”, 3. “cubic”)

  • distance_tol (float) – maximum distance for raster points from mesh nodes. If distance is larger, raster point will be set to NaN

Returns

new_grid_data/grid_data (np.ndarray) – data at raster points. Is NaN at points further from mesh node than distance_tol, if distance_tol > 0. Otherwise, raster points are interpolated according to scipy.spatial.griddata, stopping at the mesh’s convex hull

write_tiff#

flowmeshreader.write_tiff(output_file_path: str, new_grid_data: numpy.ndarray, bounds: numpy.ndarray, epsg: int) → None[source]#

Saves new_grid_data to a tiff file. new_grid_data should be a raster.

Parameters

  • output_file_path (str) – location of the output file

  • new_grid_data (np.ndarray) – data at grid points

  • bounds (np.ndarray) – outermost coordinates of the raster (west, east, south, north)

  • epsg (int) – coordinate reference system (CPS) that is stored in the tiff-file

Returns

None

mesh_to_tiff#

flowmeshreader.mesh_to_tiff(data: numpy.ndarray, input_file_path: str, output_file_path: str, resolution: float, distance_tol: float, interpolation: str = 'nearest') → None[source]#

Wrapper function that turns mesh data into a tiff. The mesh data should be a 1D array, with the same size as the coordinates in the netCDF input file.

Parameters

  • data (np.ndarray) – data at the mesh nodes.

  • input_file_path (str) – location of the input file

  • output_file_path (str) – location of the output file

  • resolution (float) – resolution of the raster

  • distance_tol (float) – maximum distance for raster points from mesh nodes. If distance is larger, raster point will be set to NaN

  • interpolation (str) – interpolation method for scipy.spatial.griddata. (1. “linear”, 2. “nearest”, 3. “cubic”)

Returns

  • grid_x (np.ndarray) – grid with x-coordinates of raster

  • grid_y (np.ndarray) – grid with y-coordinates of raster

  • new_grid_data (np.ndarray) – new_grid_data