# %%
# ======================================================================================
# Copyright (©) 2014-2026 Laboratoire Catalyse et Spectrochimie (LCS), Caen, France.
# CeCILL-B FREE SOFTWARE LICENSE AGREEMENT
# See full LICENSE agreement in the root directory.
# ======================================================================================
# ruff: noqa
"""
Processing Relaxation measurement
=================================
Processing NMR spectra taken for relaxation measurements
"""

# %%
# Import API
# ----------
import spectrochempy as scp

# short version of the unit registry
U = scp.ur

# %%
# Importing a pseudo 2D NMR spectra
# ---------------------------------
# Define the folder where are the spectra
datadir = scp.preferences.datadir
nmrdir = datadir / "nmrdata" / "bruker" / "tests" / "nmr"

dataset = scp.read_topspin(nmrdir / "relax" / "100" / "ser", use_list="vdlist")

# %%
# Analysing the data
# ---------------------
# Print dataset summary
dataset

# %%
# Plot the dataset
ds = dataset.em(lb=15 * U.Hz)
ds = ds.fft()
ds = ds.pk(phc0=-10 * U.deg, phc1=0 * U.deg)
ds.plot(xlim=(-60, -140))
# %%
# Integrate a region
dsint = ds[:, -90.0:-115.0].simpson()
dsint.plot(marker="^", ls=":")
dsint.real

# %%
# Fit a model
# -----------
# create an Optimize object using a simple leastsq method
fitter = scp.Optimize(log_level="INFO", method="leastsq")


# %%
# Define the model to fit
def T1_model(t, I0, T1):  # no underscore in parameters names.
    # T1 relaxation model
    import numpy as np

    I = I0 * (1 - np.exp(-t / T1))
    return I


# %%
# Add the model to the fitter usermodels as it it not a built-in model
fitter.usermodels = {"T1_model": T1_model}

# %%
# Define the parameter variables using a script
# (parameter: value, low_bound,  high_bound)
# no underscore in parameters names.
fitter.script = """
MODEL: T1
shape: T1_model
  $ I0:  1000.0, 1, none
  $ T1:  2.0,    0.1, none
"""

# %%
# Performs the fit
fitter.fit(dsint)

# %%
som = fitter.predict()
som

# %%
fitter.plotmerit(dsint, som, method="scatter", title="T1 relaxation fitting")

# %%
# This ends the example ! The following line can be removed or commented
# when the example is run as a notebook (`.ipynb`).

# scp.show()