xarray extension

class pangaea.LSMGridReader(xarray_obj)[source]

This is an extension for xarray specifically designed for land surface models.

Read with pangaea example:

import pangaea as pa

with pa.open_mfdataset('/path/to/ncfiles/*.nc',
                       lat_var='lat',
                       lon_var='lon',
                       time_var='time',
                       lat_dim='lat',
                       lon_dim='lon',
                       time_dim='time') as xds:
    print(xds.lsm.projection)

Read with xarray example:

import xarray as xr

with pa.open_dataset('/path/to/file.nc') as xds:
    print(xds.lsm.projection)
affine

The affine for the transformation.

Type:Affine()
center

Return the geographic center point of this dataset.

coords

Returns y, x coordinate arrays

Warning

The grids always be returned with [0,0] as Northeast and [-1,-1] as Southwest.

datetime

Get datetime object for time variable

dx

Pixel size in x direction.

Type:float
dy

Pixel size in y direction.

Type:float
epsg

EPSG code

Type:str
geotransform

The geotransform for grid.

Type:tuple
getvar(variable, yslice=slice(None, None, None), xslice=slice(None, None, None), calc_4d_method=None, calc_4d_dim=None)[source]

Get variable from model with subset options.

Warning

The grids will always be returned with [0,0] as Northeast and [-1,-1] as Southwest.

Parameters:
  • variable (str) – Name of variable in dataset.
  • yslice (slice, optional) – Slice in y-direction of grid to extract data from.
  • xslice (slice, optional) – Slice in x-direction of grid to extract data from.
  • calc_4d_method (str) – Method to convert 4D variables to 3D variables (Ex. ‘mean’, ‘min’, or ‘max’).
  • calc_4d_dim (str) – Dimension to reduce grid from 4D to 3D (Ex. ‘top_bottom’).
Returns:
Return type:

xarray.DataArray()
latlon

Returns lat,lon arrays

Warning

The grids always be returned with [0,0] as Northeast and [-1,-1] as Southwest.

projection

osgeo.osr.SpatialReference() The projection for the dataset.

resample(variable, match_grid)[source]

Resample data to grid.

Parameters:
  • variable (str) – Name of variable in dataset.
  • match_grid (gdal.Dataset() or sloot.grid.GDALGrid()) – Grid you want the data resampled to match resolution. You can also pass the path to the grid.
to_datetime()[source]

Converts time to datetime.

to_projection(variable, projection)[source]

Convert Grid to New Projection.

Parameters:
  • variable (str) – Name of variable in dataset.
  • projection (osr.SpatialReference()) – Projection to convert data to.
Returns:
Return type:

xarray.Dataset()
to_tif(variable, time_index, out_path)[source]

Dump a variable at a time index to a geotiff.

Parameters:
  • variable (str) – Name of variable in dataset.
  • time_index (int) – 0-based time index,
  • out_path (str) – Path to output geotiff file,
to_utm(variable)[source]

Convert Grid to UTM projection at center of grid.

Parameters:variable (str) – Name of variable in dataset.
Returns:
Return type:xarray.Dataset()
x_size

Number of columns in the dataset.

Type:int
y_inverted

Is the y-coord inverted

y_size

Number of rows in the dataset.

Type:int