× ⚠️ You are reading the development version documentation.
Read here the documentation of the last stable release.

Build synthetic concentration profiles

This example shows two convenient ways to build simple synthetic profiles directly with the SpectroChemPy API:

• explicit analytical expressions with top-level math aliases such as scp.exp(...);

• direct line-shape helpers such as scp.gaussian(...) when a built-in model already matches the target profile.

import spectrochempy as scp

Build a shared time axis and three simple concentration profiles with scp.exp(...).

time = scp.linspace(0.0, 1.0, 200)

c1 = scp.exp(-0.5 * ((time - 0.25) / 0.10) ** 2)
c2 = 0.8 * scp.exp(-0.5 * ((time - 0.55) / 0.12) ** 2)
c3 = 0.6 * scp.exp(-0.5 * ((time - 0.82) / 0.08) ** 2)

Assemble the 1D profiles as columns of a concentration matrix.

profiles = scp.stack([c1, c2, c3], axis=1)
profiles.y = scp.Coord(labels=["A", "B", "C"], title="species")
profiles.name = "concentrations"
profiles.title = "relative concentration"

_ = profiles.plot(legend=profiles.y.labels, colormap=None)

The same workflow can also use the built-in Gaussian line-shape helper when that reads more naturally for the problem at hand.

profiles_gaussian = scp.stack(
    [
        scp.gaussian(time, ampl=1.0, pos=0.25, width=0.235),
        scp.gaussian(time, ampl=0.8, pos=0.55, width=0.282),
        scp.gaussian(time, ampl=0.6, pos=0.82, width=0.188),
    ],
    axis=1,
)
profiles_gaussian.y = scp.Coord(labels=["A", "B", "C"], title="species")
profiles_gaussian.name = "concentrations_gaussian"
profiles_gaussian.title = "relative concentration"

_ = profiles_gaussian.plot(legend=profiles_gaussian.y.labels, colormap=None)