Posted as an answer to https://tex.stackexchange.com/q/44868.
\documentclass[tikz]{standalone}
\begin{document}
\begin{tikzpicture}[scale=0.6]
\foreach \y [count=\n] in {
{74,25,39,20,3,3,3,3,3},
{25,53,31,17,7,7,2,3,2},
{39,31,37,24,3,3,3,3,3},
{20,17,24,37,2,2,6,5,5},
{3,7,3,2,12,1,0,0,0},
{3,7,3,2,1,36,0,0,0},
{3,2,3,6,0,0,45,1,1},
{3,3,3,5,0,0,1,23,1},
{3,2,3,5,0,0,1,1,78},
} {
% column labels
\ifnum\n<10
\node[minimum size=6mm] at (\n, 0) {\n};
\fi
% heatmap tiles
\foreach \x [count=\m] in \y {
\node[fill=yellow!\x!purple, minimum size=6mm, text=white] at (\m,-\n) {\x};
}
}
% row labels
\foreach \a [count=\i] in {a,b,c,d,e,f,g,h,i} {
\node[minimum size=6mm] at (0,-\i) {\a};
}
\end{tikzpicture}
\end{document}
#import "@preview/cetz:0.3.2": canvas, draw
#set page(width: auto, height: auto, margin: 3pt)
#canvas({
import draw: rect, content
let cell-size = .7 // Size of each heatmap cell
let data = (
(74, 25, 39, 20, 3, 3, 3, 3, 3),
(25, 53, 31, 17, 7, 7, 2, 3, 2),
(39, 31, 37, 24, 3, 3, 3, 3, 3),
(20, 17, 24, 37, 2, 2, 6, 5, 5),
(3, 7, 3, 2, 12, 1, 0, 0, 0),
(3, 7, 3, 2, 1, 36, 0, 0, 0),
(3, 2, 3, 6, 0, 0, 45, 1, 1),
(3, 3, 3, 5, 0, 0, 1, 23, 1),
(3, 2, 3, 5, 0, 0, 1, 1, 78),
)
let row-labels = ("a", "b", "c", "d", "e", "f", "g", "h", "i")
// Draw column labels (1-9)
for col in range(9) {
content(
((col + 1) * cell-size, 0),
str(col + 1),
name: "col-label-" + str(col + 1),
)
}
// Draw row labels (a-i)
for row in range(9) {
content(
(0, -(row + 1) * cell-size),
row-labels.at(row),
name: "row-label-" + row-labels.at(row),
)
}
// Draw heatmap cells
for row in range(9) {
for col in range(9) {
let value = data.at(row).at(col)
rect(
((col + 1) * cell-size - cell-size / 2, -(row + 1) * cell-size - cell-size / 2),
((col + 1) * cell-size + cell-size / 2, -(row + 1) * cell-size + cell-size / 2),
fill: rgb(
// Purple (90%, 70%, 90%) to Yellow (90%, 90%, 70%)
90%, // Red stays constant at 90% for pastel effect
50% + value / 78 * 20%, // Green increases with value
50% - value / 78 * 20%, // Blue decreases with value
),
name: "cell-" + str(row) + "-" + str(col),
)
content(
((col + 1) * cell-size, -(row + 1) * cell-size),
text(fill: if value < 40 { white } else { black }, str(value)),
name: "value-" + str(row) + "-" + str(col),
)
}
}
})