Dfsu 2D

2D horizontal.

See Dfsu in MIKE IO Documentation

import numpy as np
import pandas as pd
import mikeio

Basic properties

Note

Example data can be found in the mini_book/data folder in this zip-file.

fn = "data/oresundHD_run1.dfsu"
dfs = mikeio.open(fn)
dfs

Dfsu2D
number of elements: 3612
number of nodes: 2046
projection: UTM-33
items:
  0:  Surface elevation <Surface Elevation> (meter)
  1:  Total water depth <Water Depth> (meter)
  2:  U velocity <u velocity component> (meter per sec)
  3:  V velocity <v velocity component> (meter per sec)
time: 5 steps with dt=86400.0s
      2018-03-07 00:00:00 -- 2018-03-11 00:00:00

dfs.geometry

Flexible Mesh Geometry: Dfsu2D
number of nodes: 2046
number of elements: 3612
projection: UTM-33

dfs.geometry.plot();

dfs.n_items

4

dfs.projection_string

'UTM-33'

dfs.timestep    # in seconds ...

86400.0

ds = dfs.read(items="Surface elevation")
ds.shape

(5, 3612)

da = ds["Surface elevation"]   # =ds[0] = ds.Surface_elevation
da

<mikeio.DataArray>
name: Surface elevation
dims: (time:5, element:3612)
time: 2018-03-07 00:00:00 - 2018-03-11 00:00:00 (5 records)
geometry: Dfsu2D (3612 elements, 2046 nodes)

da.plot();

Subset data

ze = dfs.element_coordinates[:,2]    # third column is depth
ze<-20

array([False, False, False, ..., False, False, False])

elems = np.where(ze<-20)[0]
ds_sub = dfs.read(items=0, time=-1, elements=elems)    # read only data where depth is more than 20m
ds_sub

<mikeio.Dataset>
dims: (element:202)
time: 2018-03-11 00:00:00 (time-invariant)
geometry: Dfsu2D (202 elements, 166 nodes)
items:
  0:  Surface elevation <Surface Elevation> (meter)

ax = ds_sub[0].plot()
dfs.geometry.plot.mesh(ax=ax);

Create new dfsu from mesh

fn = "data/two_elements.mesh"
dfs = mikeio.open(fn)

data = 36.5 * np.ones(dfs.n_elements)            # set all elements to 36.5
time = pd.date_range("2020-1-1", periods=1)      # arbitrary date 
item = mikeio.ItemInfo(mikeio.EUMType.Chezy_No)
da = mikeio.DataArray(data, time=time, item=item, geometry=dfs.geometry)

da.to_dfs("chezy_map.dfsu")

dfs = mikeio.open("chezy_map.dfsu")
dfs.read()[0][0,:]

<mikeio.DataArray>
name: Chezy No
dims: (element:2)
time: 2020-01-01 00:00:00 (time-invariant)
geometry: Dfsu2D (2 elements, 4 nodes)
values: [36.5, 36.5]

More examples

See the MIKE IO example notebooks which has “dfsu” in the name.