## ----include = FALSE----------------------------------------------------------
knitr::opts_chunk$set(
  collapse = TRUE,
  comment = "#>",
  fig.width  = 5,
  fig.height = 5
)

## ----setup, message = FALSE---------------------------------------------------
library(gghinton)
library(ggplot2)

## ----heatmap-example----------------------------------------------------------
set.seed(7)
nr <- 10
nc <- 18
W <- matrix(rnorm(nr*nc, sd = 0.4), nrow = nr, ncol = nc)
rownames(W) <- paste0("neuron_", 1:nr)
colnames(W) <- paste0("input_",  1:nc)

# The standard heatmap approach
df <- as.data.frame(as.table(W))
names(df) <- c("row", "col", "value")

ggplot(df, aes(x = col, y = row, fill = value)) +
  geom_tile() +
  scale_fill_gradient2(low = "blue", mid = "white", high = "red",
                       midpoint = 0) +
  coord_fixed() +
  theme_minimal() +
  theme(panel.grid = element_blank(), 
        axis.text.x = element_text(angle = 45, vjust = 1, hjust=1)) +
  labs(title = "Weight matrix as a heatmap")

## ----hinton-example-----------------------------------------------------------
df_h <- matrix_to_hinton(W,
  rowname_col = "row", colname_col = "col", value_col = "weight")

ggplot(df_h, aes(x = col, y = row, weight = weight)) +
  geom_hinton() +
  scale_fill_hinton() +
  scale_x_continuous(breaks = seq_along(colnames(W)), labels = colnames(W)) +
  scale_y_continuous(breaks = seq_along(rownames(W)), labels = rev(rownames(W))) +
  coord_fixed() +
  theme_hinton() +
  theme(axis.text.x = element_text(angle = 45, vjust = 1, hjust=1))+
  labs(title = "Weight matrix as a Hinton diagram")

## ----correlation-example------------------------------------------------------
set.seed(3)
# Simulate a correlation matrix
S <- matrix(c(
   1.00,  0.72, -0.35,  0.15,
   0.72,  1.00, -0.21,  0.08,
  -0.35, -0.21,  1.00, -0.58,
   0.15,  0.08, -0.58,  1.00
), 4, 4)
vars <- c("IQ", "Memory", "Anxiety", "Stress")
rownames(S) <- colnames(S) <- vars

df_cor <- matrix_to_hinton(S)

ggplot(df_cor, aes(x = col, y = row, weight = weight)) +
  geom_hinton() +
  scale_fill_hinton() +
  scale_x_continuous(breaks = 1:4, labels = vars) +
  scale_y_continuous(breaks = 1:4, labels = rev(vars)) +
  coord_fixed() +
  theme_hinton() +
  labs(title = "Correlation matrix",
       subtitle = "White = positive, black = negative")