Custom Heatmap

Authors

[Editor] Hu Zheng;

[Contributors]

Custom Heatmap, directly plot a heatmap based on the given data.

Setup

System Requirements: Cross-platform (Linux/MacOS/Windows)
Programming language: R
Dependent packages: ggplot2

# Install packages
if (!requireNamespace("ggplot2", quietly = TRUE)) {
  install.packages("ggplot2")
}

# Load packages
library(ggplot2)

Data Preparation

The case data is a grayscale image of the official logo of hiplot.org.

# Load data
data <- read.delim("files/Hiplot/034-custom-heat-map-data.txt", header = T)

# convert data structure
draw_data <- as.matrix(data[, 2:ncol(data)])
row_num <- nrow(draw_data)
col_num <- ncol(draw_data)
col_labels <- colnames(data)
col_labels <- col_labels[2:ncol(data)]
row_labels <- data$name
rm(data)
df <- expand.grid(row = 1:row_num, col = 1:col_num)
df$value <- c(draw_data)

# View data
head(df)

  row col value
1   1   1   236
2   2   1   236
3   3   1   236
4   4   1   236
5   5   1   236
6   6   1   236

Visualization

# Custom Heatmap
p <- ggplot(df, aes(x = col, y = row, fill = value)) +
  geom_point(shape = 21, size = 8, aes(fill = value), color = "white") +
  scale_fill_gradient(low = "#DDDDDD", high = "#0000F5") +
  guides(fill = guide_colorbar(title = "Value")) +
  theme(
    panel.background = element_rect(fill = "white"),
    panel.grid = element_blank(),
    axis.text = element_text(size = 10),
    axis.ticks = element_blank(),
    axis.title = element_blank()
    ) +
  scale_x_continuous(breaks = 1:col_num, labels = col_labels, position = "top") +
  scale_y_reverse(breaks = 1:row_num, labels = row_labels, position = "left")

p