× ⚠️ 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 profiles with analytical expressions

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 as columns of a concentration matrix:

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

ax = profiles.T.plot()
ax.legend()

<matplotlib.legend.Legend object at 0x7fdc94570190>

Use built-in Gaussian line-shape helper

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

ax = profiles_gaussian.T.plot()
ax.legend()

<matplotlib.legend.Legend object at 0x7fdc85537250>