Effacer les filtres
Effacer les filtres

How to color the colormap with a set of hexadecimal colors?

85 vues (au cours des 30 derniers jours)
Sujata Dhar
Sujata Dhar le 14 Déc 2022
Commenté : Toshia M le 30 Avr 2024 à 22:26
I want to colormap to plot data. I want to use a set of hexadecimal code for the colors of the plot. If I run with following code, I get the plot.
map=[1 0.9 0; 1 0.75 0; 1 0.625 0; 1 0.5 0; 1 0.375 0; 1 0.25 0; 1 0.125 0; 1 0 0];
colormap(map);
But instead I want to use the following set of hexadecimal codes for the plot, for eg.
map = ('#E1F2E3','#CDE5D2','#9CCEA7','#6CBA7D','#40AD5A','#22BB3B','#06592A');
But I run into error stating that
"Error using colormap
Colormap must have 3 columns: [R,G,B]."
How should I solve this issue, please.

Réponse acceptée

Dave B
Dave B le 14 Déc 2022
Modifié(e) : Dave B le 14 Déc 2022
Starting in R2020b you can use the validatecolor function to convert hex to rgb (using the 'multiple' option to convert more than one color):
map = {'#E1F2E3','#CDE5D2','#9CCEA7','#6CBA7D','#40AD5A','#22BB3B','#06592A'};
cmap = validatecolor(map, 'multiple')
cmap = 7×3
0.8824 0.9490 0.8902 0.8039 0.8980 0.8235 0.6118 0.8078 0.6549 0.4235 0.7294 0.4902 0.2510 0.6784 0.3529 0.1333 0.7333 0.2314 0.0235 0.3490 0.1647
imagesc(peaks)
colormap(cmap)
colorbar
  3 commentaires
Toshia M
Toshia M le 30 Avr 2024 à 22:26
Starting in R2024a, you can use the hex2rgb function to convert hexadecimal color codes to RGB triplets. This provides an alternative way to create a colormap from a set of hexadecimal values, but you can also use the function any time you want to calculate the equivalent RGB triplet from a hexadecimal color code.
map = {'#E1F2E3','#CDE5D2','#9CCEA7','#6CBA7D','#40AD5A','#22BB3B','#06592A'};
cmap = hex2rgb(map)
cmap = 7x3
0.8824 0.9490 0.8902 0.8039 0.8980 0.8235 0.6118 0.8078 0.6549 0.4235 0.7294 0.4902 0.2510 0.6784 0.3529 0.1333 0.7333 0.2314 0.0235 0.3490 0.1647
<mw-icon class=""></mw-icon>
<mw-icon class=""></mw-icon>
You can also go the other way by calling the rgb2hex function. For example, you can convert five colors from the parula colormap to hexadecimal color codes:
p5 = parula(5);
pHex = rgb2hex(p5)
pHex = 5x1 string array
"#3E26A8" "#347AFD" "#12BEB9" "#C8C129" "#F9FB15"

Connectez-vous pour commenter.

Plus de réponses (1)

Bora Eryilmaz
Bora Eryilmaz le 14 Déc 2022
Modifié(e) : Bora Eryilmaz le 14 Déc 2022
You can use a function like this in a loop:
map = {'E1F2E3','CDE5D2','9CCEA7','6CBA7D','40AD5A','22BB3B','06592A'}
map = 1×7 cell array
{'E1F2E3'} {'CDE5D2'} {'9CCEA7'} {'6CBA7D'} {'40AD5A'} {'22BB3B'} {'06592A'}
N = numel(map);
newMap = zeros(N,3);
for i = 1:N
newMap(i,:) = hex2rgb(map{i});
end
newMap
newMap = 7×3
225 242 227 205 229 210 156 206 167 108 186 125 64 173 90 34 187 59 6 89 42
function result = hex2rgb(h)
d = hex2dec(h);
r = bitshift(bitand(d, 0xFF0000), -16);
g = bitshift(bitand(d, 0x00FF00), -8);
b = bitshift(bitand(d, 0x0000FF), 0);
result = [r, g, b];
end

Catégories

En savoir plus sur Colormaps dans Help Center et File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by