colorbar

named_arrays.colorsynth.colorbar(spd, wavelength=None, axis=None, spd_min=None, spd_max=None, spd_norm=None, wavelength_min=None, wavelength_max=None, wavelength_norm=None)

A thin wrapper around colorsynth.colorbar() for named arrays.

Parameters:

• spd (AbstractArray) – A spectral power distribution to convert to a RGB array.

• wavelength (None | AbstractScalar) – The wavelength coordinates corresponding to the spectral power distribution. If None (the default), the wavelength is assumed to be evenly sampled over the human visible range.

• axis (None | str) – The logical axis corresponding to changing wavelength. If None (the default), spd must be one-dimensional.

• spd_min (None | int | float | complex | ndarray | Quantity | AbstractArray) – The value of the spectral power distribution representing minimum intensity

• spd_max (None | int | float | complex | ndarray | Quantity | AbstractArray) – The vale of the spectral power distribution representing maximum intensity

• spd_norm (None | Callable) – An optional function that transforms the spectral power distribution values before mapping to RGB.

• wavelength_min (None | int | float | complex | ndarray | Quantity | AbstractScalar) – The wavelength value that is mapped to the minimum wavelength of the human visible color range, 380 nm.

• wavelength_max (None | int | float | complex | ndarray | Quantity | AbstractScalar) – The wavelength value that is mapped to the maximum wavelength of the human visible color range, 700 nm

• wavelength_norm (None | Callable) – An optional function to transform the wavelength values before they are mapped into the human visible color range.

Return type:

FunctionArray[Cartesian2dVectorArray, AbstractScalar]

See also

colorsynth.colorbar()

Equivalent function for instances of numpy.ndarray.

Examples

Plot the colorbar of a random, 3D cube.

import matplotlib.pyplot as plt
import astropy.units as u
import astropy.visualization
import named_arrays as na

# Define a random 3d cube
a = na.random.uniform(
    low=0 * u.photon,
    high=1000 * u.photon,
    shape_random=dict(x=16, y=16, wavelength=11),
)

# Define wavelength axis
wavelength = na.linspace(
    start=100 * u.AA,
    stop=200 * u.AA,
    axis="wavelength",
    num=a.shape["wavelength"],
)

# Compute the colorbar corresponding to the random 3d cube.
colorbar = na.colorsynth.colorbar(
    spd=a,
    wavelength=wavelength,
    axis="wavelength",
)

# Plot the colorbar
with astropy.visualization.quantity_support():
    fig, ax = plt.subplots()
    na.plt.pcolormesh(
        C=colorbar,
        axis_rgb="wavelength",
        ax=ax,
    )