Sine bell and squared Sine bell window multiplication

In this example, we use sine bell or squared sine bell 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

DATADIR = scp.preferences.datadir
path = DATADIR / "nmrdata" / "bruker" / "tests" / "nmr" / "topspin_1d"

dataset1D = scp.nmr.read_topspin(path, expno=1, remove_digital_filter=True)
dataset1D

/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_sp.py", line 31, in <module>
    dataset1D /= dataset1D.real.data.max()  # normalize
                 ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'real'

Apply Sine bell window apodization with parameter ssb=2, which correspond to a cosine function

new1, curve1 = scp.sinm(dataset1D, ssb=2, retapod=True, inplace=False)

this is equivalent to

new1, curve1 = dataset1D.sinm(ssb=2, retapod=True, inplace=False)

or also

new1, curve1 = scp.sp(dataset1D, ssb=2, pow=1, retapod=True, inplace=False)

Apply Sine bell window apodization with parameter ssb=2, which correspond to a sine function

new2, curve2 = dataset1D.sinm(ssb=1, retapod=True, inplace=False)

Apply Squared Sine bell window apodization with parameter ssb=1 and ssb=2

new3, curve3 = scp.qsin(dataset1D, ssb=2, retapod=True, inplace=False)
new4, curve4 = dataset1D.qsin(ssb=1, retapod=True, inplace=False)

Apply shifted Sine bell window apodization with parameter ssb=8 (mixed sine/cosine window)

new5, curve5 = dataset1D.sinm(ssb=8, retapod=True, inplace=False)

Plotting

dataset1D.plot(zlim=(-2, 2), color="k")
curve1.plot(color="r", clear=False)
new1.plot(
    data_only=True, color="r", clear=False, label=" sinm with ssb= 2 (cosine window)"
)
curve2.plot(color="b", clear=False)
new2.plot(
    data_only=True, color="b", clear=False, label=" sinm with ssb= 1 (sine window)"
)
curve3.plot(color="m", clear=False)
new3.plot(data_only=True, color="m", clear=False, label=" qsin with ssb= 2")
curve4.plot(color="g", clear=False)
new4.plot(data_only=True, color="g", clear=False, label=" qsin with ssb= 1")
curve5.plot(color="c", ls="--", clear=False)
new5.plot(
    data_only=True,
    color="c",
    ls="--",
    clear=False,
    label=" sinm with ssb= 8",
    legend="best",
)

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