#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""
Rb2SO4, 87Rb (I=3/2) QMAT
^^^^^^^^^^^^^^^^^^^^^^^^^

87Rb (I=3/2) Quadrupolar Magic-angle turning (QMAT)
simulation.
"""
# %%
# The following is a simulation of the QMAT spectrum of :math:`\text{Rb}_2\text{SiO}_4`.
# The 2D QMAT spectrum is a correlation of finite speed MAS to an infinite speed MAS
# spectrum. The parameters for the simulation are obtained from Walder `et. al.` [#f1]_.
import matplotlib as mpl
import matplotlib.pyplot as plt
from mrsimulator import Simulator, SpinSystem, Site
from mrsimulator.methods import SSB2D

# global plot configuration
font = {"size": 9}
mpl.rc("font", **font)
mpl.rcParams["figure.figsize"] = [4.5, 3.0]
# sphinx_gallery_thumbnail_number = 1

# %%
# Generate the site and spin system objects.
sites = [
    Site(
        isotope="87Rb",
        isotropic_chemical_shift=16,  # in ppm
        quadrupolar={"Cq": 5.3e6, "eta": 0.1},  # Cq in Hz
    ),
    Site(
        isotope="87Rb",
        isotropic_chemical_shift=40,  # in ppm
        quadrupolar={"Cq": 2.6e6, "eta": 1.0},  # Cq in Hz
    ),
]
spin_systems = [SpinSystem(sites=[s]) for s in sites]

# %%
# Use the ``SSB2D`` method to simulate a PASS, MAT, QPASS, QMAT, or any equivalent
# sideband separation spectrum. Here, we use the method to generate a QMAT spectrum.
# The QMAT method is created from the ``SSB2D`` method in the same as a PASS or MAT
# method. The difference is that the observed channel is a half-integer quadrupolar
# spin instead of a spin I=1/2.
qmat = SSB2D(
    channels=["87Rb"],
    magnetic_flux_density=9.4,
    rotor_frequency=2604,
    spectral_dimensions=[
        {
            "count": 32 * 4,
            "spectral_width": 2604 * 32,  # in Hz
            "label": "Anisotropic dimension",
        },
        {
            "count": 512,
            "spectral_width": 50000,  # in Hz
            "label": "High speed MAS dimension",
        },
    ],
)

# %%
# Create the Simulator object, add the method and spin system objects, and
# run the simulation.
sim = Simulator()
sim.spin_systems = spin_systems  # add the spin systems
sim.methods = [qmat]  # add the method.

# For 2D spinning sideband simulation, set the number of spinning sidebands in the
# Simulator.config object to `spectral_width/rotor_frequency` along the sideband
# dimension.
sim.config.number_of_sidebands = 32
sim.run()

# %%
# The plot of the simulation.
data = sim.methods[0].simulation
ax = plt.subplot(projection="csdm")
cb = ax.imshow(data / data.max(), aspect="auto", cmap="gist_ncar_r", vmax=0.15)
plt.colorbar(cb)
ax.invert_xaxis()
ax.set_ylim(200, -200)
plt.tight_layout()
plt.show()

# %%
# .. [#f1] Walder, B. J., Dey, K .K, Kaseman, D. C., Baltisberger, J. H., and Philip J.
#       Grandinetti. Sideband separation experiments in NMR with phase incremented echo
#       train acquisition, J. Chem. Phys. (2013) **138**, 174203.
#       `DOI:10.1063/1.4803142 <https://doi.org/10.1063/1.4803142>`_