Exponential window multiplication

In this example, we perform exponential window multiplication to apodize a NMR signal in the time domain.

Requires the official spectrochempy-nmr plugin. Install with: pip install spectrochempy[nmr].

import spectrochempy as scp

Hz = scp.ur.Hz
us = scp.ur.us

path = scp.preferences.datadir / "nmrdata" / "bruker" / "tests" / "nmr" / "topspin_1d"
dataset1D = scp.nmr.read_topspin(path, expno=1, remove_digital_filter=True)

/home/runner/work/spectrochempy/spectrochempy/.venv/lib/python3.13/site-packages/spectrochempy/core/readers/importer.py:226: UserWarning: No module named 'spectrochempy_hypercomplex'
  warning_(str(e))

Normalize the dataset values and reduce the time domain

dataset1D /= dataset1D.real.data.max()  # normalize
dataset1D = dataset1D[0.0:15000.0]

Traceback (most recent call last):
  File "/home/runner/work/spectrochempy/spectrochempy/build/~gallery_examples/processing/apodization/plot_proc_em.py", line 30, in <module>
    dataset1D /= dataset1D.real.data.max()  # normalize
                 ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'real'

Apply exponential window apodization

new1, curve1 = scp.em(dataset1D.copy(), lb=20 * Hz, retapod=True, inplace=False)

Apply a shifted exponential window apodization default units are HZ for broadening and microseconds for shifting

new2, curve2 = dataset1D.copy().em(
    lb=100 * Hz, shifted=10000 * us, retapod=True, inplace=False
)

Plotting

dataset1D.plot(zlim=(-2, 2), color="k")
curve1.plot(color="r")
new1.plot(color="r", clear=False, label=" em = 20 hz")
curve2.plot(color="b", clear=False)
new2.plot(dcolor="b", clear=False, label=" em = 30 HZ, shifted = ")

This ends the example ! The following line can be uncommented if no plot shows when running the .py script with python scp.show()

sphinx_gallery_thumbnail_number = -1