The function hclplot is an auxiliary function for illustrating the trajectories of color palettes in two-dimensional HCL space projections. It collapses over one of the three coordinates (either the hue H or the luminance L) and displays a heatmap of colors combining the remaining two dimensions. The coordinates for the given color palette are highlighted to bring out its trajectory.
The function hclplot has been designed to work well with the hcl_palettes in this package. While it is possible to apply it to other color palettes as well, the results might look weird or confusing if these palettes are constructed very differently.
More specifically, the following palettes can be visualized well:
Qualitative with (approximately) constant luminance. In this case, hclplot shows a hue-chroma plane (in polar coordinates), keeping luminance at a fixed level (by default displayed in the main title of the plot). If the luminance is, in fact, not approximately constant, the luminance varies along with hue and chroma, using a simple linear function (fitted by least squares). hclplot shows a chroma-luminance plane, keeping hue at a fixed level (by default displayed in the main title of the plot). If the hue is, in fact, not approximately constant, the hue varies along with chroma and luminance, using a simple linear function (fitted by least squares.
Diverging with two (approximately) constant hues: This case is visualized with two back-to-back sequential displays.
To infer the type of display to use, by default, the following heuristic is used: If luminance is not approximately constant (range > 10) and follows rougly a triangular pattern, a diverging display is used. If luminance is not constant and follows roughly a linear pattern, a sequential display is used. Otherwise a qualitative display is used.
Note: Requires matplotlib to be installed.
hclplot(x, _type=None, h=None, c=None, l=None,
axes=True, linewidth=1, s=150, **kwargs)xstr, list, colorobject
_typeNone, str
"qualitative", "sequential", or "diverging"). For qualitative palettes a hue-chroma plane is used, otherwise a chroma-luminance plane. By default (_type = None) the type is inferred from the luminance trajectory corresponding to x.
hNone, int, float
[-360, 360]
cNone, int, float
lNone, int, float
axesbool
True.
linewidthint, float, None
0 or None the line connecting the colors of the palette will be suppressed.
sint, float, None
150. If set 0 or None the position of the colors of the palette will be suppressed.
**kwargs
title (str), xlabel (str), ylabel (str), figsize (forwarded to pyplot.figure). xlabel/ylabel only used for qualitative and diverging plots. A matplotlib axis can be provided via ax (object of type matplotlib.axes._axes.Axes) which allows to draw multiple HCL spaces on one figure.
No return, visualizes the palette and HCL space either on a new figure or on an existing axis (if ax is provided, see **kwargs).
# Sequential HCL palette, hclplot with all available options
from colorspace import sequential_hcl, hclplot
x = sequential_hcl("PurpOr")(5)
hclplot(x,
xlabel = "Chroma dimension",
ylabel = "Luminance dimension",
title = "hclplot Example (Sequential)",
figsize = (5, 5), s = 250);
# Multiple subplots
import matplotlib.pyplot as plt
from colorspace import sequential_hcl, hclplot
# Three different palettes
pal1 = sequential_hcl(h = 260, c = 80, l = [35, 95], power = 1)
pal2 = sequential_hcl(h = 245, c = [40, 75, 0], l = [30, 95], power = 1)
pal3 = sequential_hcl(h = 245, c = [40, 75, 0], l = [30, 95], power = [0.8, 1.4])pal1.show_settings()Class: sequential_hcl
h1 260.0
h2 260.0
c1 80.0
cmax ---
c2 0
l1 35.0
l2 95.0
p1 1.0
p2 1.0
fixup Truepal2.show_settings()Class: sequential_hcl
h1 245.0
h2 245.0
c1 40.0
cmax 75.0
c2 0.0
l1 30.0
l2 95.0
p1 1.0
p2 1.0
fixup Truepal3.show_settings()Class: sequential_hcl
h1 245.0
h2 245.0
c1 40.0
cmax 75.0
c2 0.0
l1 30.0
l2 95.0
p1 0.8
p2 1.4
fixup Truefig, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize = (12, 4))
hclplot(pal1(7), ax = ax1)
hclplot(pal2(7), ax = ax2)
hclplot(pal3(7), ax = ax3)
plt.show();
# Another example with two sequential and one
# diverging palettes with custom settings
from colorspace import sequential_hcl, diverging_hcl, hclplot
import matplotlib.pyplot as plt
pal1 = sequential_hcl(h = [260, 220], c = [50, 0, 75], l = [30, 95], power = 1)
pal2 = sequential_hcl(h = [260, 60], c = 60, l = [40, 95], power = 1)
pal3 = diverging_hcl( h = [260, 0], c = 80, l = [35, 95], power = 1)
fig, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize = (12, 4))
hclplot(pal1(7), ax = ax1)
hclplot(pal2(7), ax = ax2)
hclplot(pal3(7), ax = ax3)
plt.show();
# Another example with two sequential and one
# diverging palettes with custom settings
from colorspace import sequential_hcl, diverging_hcl, qualitative_hcl, hclplot
import matplotlib.pyplot as plt
fig, (ax1, ax2, ax3) = plt.subplots(1, 3, figsize = (12, 4))
hclplot(sequential_hcl()(7), ax = ax1)
hclplot(diverging_hcl()(7), ax = ax2)
hclplot(qualitative_hcl()(7), ax = ax3)
plt.show();
ImportError: If matplotlib is not installed.
TypeError: If argument _type is not None or str.
TypeError: If argument _type is str but not one of the allowed types.
TypeError: If argument c, and/or l are not None, str, or int.
TypeError: If argument h is neither None, int, float, or tuple, or tuple not containing int/float.
ValueError: If c,l is not None and smaller or equal to 0 (must be positive).
ValueError: If h is tuple length 0 or >2 (must be one or two).
ValueError: If h is not None and not within the range [-360, 360].
TypeError: If s, linewidth are not int, float, or None.
ValueError: If s, linewidth are int/float but negative (<0).