#!/usr/bin/env python
# coding: utf-8

# # Dfsu - spectral data
# 
# MIKE 21 SW can output full spectral information in points, along lines or in an area. In all these cases data are stored in dfsu files with additional axes: frequency and directions. 
# 
# This notebook explores reading __full__ spectral dfsu files from MIKE 21 SW as 
# 
# * point
# * line
# * area
# 

# In[1]:


import numpy as np
import matplotlib.pyplot as plt
import mikeio


# ## Read dfsu point spectrum

# In[2]:


fn = "../tests/testdata/pt_spectra.dfsu"
da = mikeio.read(fn)[0]
da


# In[3]:


da.plot(); # plots first timestep by default


# Don't like the default plot? No worries, it can be customized.

# In[4]:


ax = da.plot.patch(rmax=8);
dird = np.round(da.directions, 2)
ax.set_thetagrids(dird, labels=dird);


# ## Dfsu line spectrum
# 
# Data in dfsu line spectra is node-based contrary to must other dfsu-formats.

# In[5]:


fn = "../tests/testdata/line_spectra.dfsu"
da = mikeio.read(fn).Energy_density
da


# In[6]:


spec = da[0].isel(node=3)  # note first 3 points are outside domain
spec


# In[7]:


spec.plot(cmap="Greys", rmax=8, r_as_periods=True);


# ### Plot Hm0 on a line

# In[8]:


Hm0 = da.isel(time=0).to_Hm0()
Hm0.plot(title='Hm0 on a line crossing the domain');


# ## Dfsu area spectrum

# In[9]:


fn = "../tests/testdata/area_spectra.dfsu"
da = mikeio.read(fn, items="Energy density")[0]
da


# In[10]:


da.plot(); # default area plot is Hm0


# In[11]:


da_pt = da.sel(x=2.9, y=52.5)
da_pt


# In[12]:


da_pt.plot(rmax=9);


# ### Interactive widget for exploring spectra in different points 

# In[13]:


from ipywidgets import interact
from datetime import timedelta


# In[14]:


@interact
def plot_element(id=(0,da.geometry.n_elements-1), step=(0,da.n_timesteps-1)):
    spec = da[step,id]
    time = da.start_time + timedelta(seconds=(step*da.timestep))
    spec.plot(vmax=0.04, vmin=0, rmax=8, title=f"Wave spectrum, {time}, element: {id}");
    plt.show();


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