104 lines
3.4 KiB
Python
104 lines
3.4 KiB
Python
from abc import ABC, abstractmethod
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import numpy as np
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# the following functions are taken from Ben Southgate:
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# https://bsouthga.dev/posts/colour-gradients-with-python
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def hex_to_RGB(hex):
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""" "#FFFFFF" -> [255,255,255]"""
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# Pass 16 to the integer function for change of base
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return [int(hex[i : i + 2], 16) for i in range(1, 6, 2)]
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def RGB_to_hex(RGB):
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"""[255,255,255] -> "#FFFFFF" """
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# Components need to be integers for hex to make sense
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RGB = [int(x) for x in RGB]
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return "#" + "".join(
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["0{0:x}".format(v) if v < 16 else "{0:x}".format(v) for v in RGB]
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)
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def colour_dict(gradient):
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"""Takes in a list of RGB sub-lists and returns dictionary of
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colours in RGB and hex form for use in a graphing function
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defined later on."""
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return {
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"hex": [RGB_to_hex(RGB) for RGB in gradient],
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"r": [RGB[0] for RGB in gradient],
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"g": [RGB[1] for RGB in gradient],
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"b": [RGB[2] for RGB in gradient],
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}
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def linear_gradient(start_hex, finish_hex="#FFFFFF", n=10):
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"""returns a gradient list of (n) colours between
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two hex colours. start_hex and finish_hex
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should be the full six-digit colour string,
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inlcuding the number sign ("#FFFFFF")"""
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# Starting and ending colours in RGB form
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s = hex_to_RGB(start_hex)
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f = hex_to_RGB(finish_hex)
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# Initilize a list of the output colours with the starting colour
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RGB_list = [s]
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# Calcuate a colour at each evenly spaced value of t from 1 to n
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for t in range(0, n):
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# Interpolate RGB vector for colour at the current value of t
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curr_vector = [
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int(s[j] + (float(t) / (n - 1)) * (f[j] - s[j])) for j in range(3)
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]
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# Add it to our list of output colours
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RGB_list.append(curr_vector)
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return colour_dict(RGB_list)
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def polylinear_gradient(colours, n):
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"""returns a list of colours forming linear gradients between
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all sequential pairs of colours. "n" specifies the total
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number of desired output colours"""
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# The number of colours per individual linear gradient
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n_out = int(float(n) / (len(colours) - 1))
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# returns dictionary defined by colour_dict()
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gradient_dict = linear_gradient(colours[0], colours[1], n_out)
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if len(colours) > 1:
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for col in range(1, len(colours) - 1):
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next = linear_gradient(colours[col], colours[col + 1], n_out)
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for k in ("hex", "r", "g", "b"):
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# Exclude first point to avoid duplicates
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gradient_dict[k] += next[k][1:]
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return gradient_dict
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class ColourMap(ABC):
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@abstractmethod
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def __call__(self, v: float): ...
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class LinearGradientColourMap(ColourMap):
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def __init__(
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self,
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colours: list[str] | None = ["#ff0000", "#ffffff", "#0000ff"],
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min_value: float | None = 0,
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max_value: float | None = 1,
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bins: int = 100,
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):
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self.colours = polylinear_gradient(colours, bins)
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self.min, self.max = min_value, max_value
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def __call__(self, v: float):
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v = max(0, int((v - self.min) / (self.max - self.min) * 100) - 1)
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if v >= len(self.colours["hex"]):
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breakpoint()
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return self.colours["hex"][v]
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class RandomColourMap(ColourMap):
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def __init__(self, random_state: int | list[int] | None = [2, 3, 4, 5, 6]):
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self.rgen = np.random.default_rng(random_state)
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def __call__(self, v: float):
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return RGB_to_hex([x * 255 for x in self.rgen.random(3)])
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