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

# # Functional form
# 
# This notebook demonstrates the use of the `FunctionalForm` model to describe an exponential increase/decay from one layer to the next. The code in `functional.py` can be used as a starting point to change the exponential profile to a different analytic form.

# In[1]:


# necessary imports
get_ipython().run_line_magic('matplotlib', 'inline')

import numpy as np
import matplotlib.pyplot as plt

from refnx.reflect import Slab, SLD, Structure
from functional import FunctionalForm


# In[2]:


# some materials
si = SLD(2.07, 'Si')
poly1 = SLD(2.0, 'poly1')
poly2 = SLD(4.0, 'poly2')
d2o = SLD(6.36, 'd2o')

# increase from one to the other
poly1_l = poly1(100., 3.)
poly2_l = poly2(100., 3.)

ff = FunctionalForm(200., 30., 5., poly1_l, poly2_l)

struct = si | poly1_l| poly2_l | d2o(0, 3)
struct2 = si | poly1_l | ff | poly2_l | d2o(0, 3)

struct2.contract = 1.

plt.plot(*struct.sld_profile())
plt.plot(*struct2.sld_profile());


# In[3]:


si = SLD(2.07, 'Si')
poly1 = SLD(4.0, 'poly1')
poly2 = SLD(2.0, 'poly2')
d2o = SLD(6.36, 'd2o')

# decay from one to the other
poly1_l = poly1(100., 3.)
poly2_l = poly2(100., 3.)

ff = FunctionalForm(200., 30., 3., poly1_l, poly2_l)

struct = si | poly1_l| poly2_l | d2o(0, 3)
struct2 = si | poly1_l | ff | poly2_l | d2o(0, 3)

struct2.contract = 1.

plt.plot(*struct.sld_profile())
plt.plot(*struct2.sld_profile());


# In[4]:


si = SLD(2.07, 'Si')
poly1 = SLD(3.0, 'poly1')
d2o = SLD(6.36, 'd2o')


# In[5]:


# decay to backing solvent
poly1_l = poly1(100., 3.)
d2o_l = d2o(0, 3)

ff = FunctionalForm(200., 30., 5., poly1_l, d2o_l)

struct = si | poly1_l | d2o(0, 3)
struct2 = si | poly1_l | ff | d2o_l

struct2.contract = 1.

plt.plot(*struct.sld_profile())
plt.plot(*struct2.sld_profile());


# In[6]:


# use of the `reverse` keyword reverses the slab representation of
# this specific component
si = SLD(2.07, 'Si')
poly1 = SLD(1.0, 'poly1')
poly2 = SLD(4.0, 'poly2')
d2o = SLD(6.36, 'd2o')

# decay from one to the other
poly1_l = poly1(100., 3.)
poly2_l = poly2(100., 3.)

ff = FunctionalForm(200., 30., 3., poly1_l, poly2_l, reverse=True)

struct = si | poly1_l| poly2_l | d2o(0, 3)
struct2 = si | poly1_l | ff | poly2_l | d2o(0, 3)

struct2.contract = 1.

plt.plot(*struct.sld_profile())
plt.plot(*struct2.sld_profile());


# In[7]:


# use of the `reverse` keyword reverses the slab representation of
# this specific component
si = SLD(2.07, 'Si')
poly1 = SLD(4.0, 'poly1')
poly2 = SLD(1.5, 'poly2')
d2o = SLD(6.36, 'd2o')

# decay from one to the other
poly1_l = poly1(100., 3.)
poly2_l = poly2(100., 3.)

ff = FunctionalForm(200., 30., 3., poly1_l, poly2_l, reverse=True)

struct = si | poly1_l| poly2_l | d2o(0, 3)
struct2 = si | poly1_l | ff | poly2_l | d2o(0, 3)

struct2.contract = 1.

plt.plot(*struct.sld_profile())
plt.plot(*struct2.sld_profile());