CODEWITHSUNDEEP
rmatrixggplot2
TZH
TZH

Reputation: 83

How to plot heatmap using 2 matrix in r

I am trying to create a heatmap, but am confused as to how to. Here are the dataframes. 

Ticker <- c("S&P 500","Dow Jones Index","AAPL","MSFT","FB","NFLX","GOOG","JPM","TSLA")
Values <- c(2, 1, 1, 1, 1, 1, 1, -1, -1)

ticker_matrix <- matrix(Ticker , nrow = 3, ncol = 3)
values_matrix <- matrix(Values, nrow = 3, ncol = 3)

How should i use ggplot2 to plot a heat map that looks like this?

enter image description here

the matrix plot is a 3x3 matrix whereby positive numbers are in green (the larger the number, the darker the green), and negative number in red, it will be even better.

Edit:

Thanks Camille for highlighting the broadness of the question, i shall narrow down the question further by making reference to d.b's answer.

d.b's answer is in the exact direction i am seeking. whereby the heatmap is shown in a 3x3 matrix based on the scale of underlying value in the background. (the purpose of this visualization is to show how positive or negative a particular stock's sentiment is)

Building on d.b's answer (whereby values are colored in discrete factors), i will post an alternative solution with continuous variables on the scale. Thanks all!

Upvotes: 1

Views: 879

Answers (2)

TZH
TZH

Reputation: 83

continuous variable version (range from c(-1,2)) of d.b's answer:

d = data.frame(Ticker = as.vector(ticker_matrix),
           Values = as.numeric(values_matrix),
           X = as.vector(row(ticker_matrix)),
           Y = as.vector(col(ticker_matrix)))

ggplot(data = d,
   mapping = aes(x = factor(X),
                 y = factor(Y),
                 fill = Values,
                 label = Ticker)) +
    geom_tile() +
    geom_text() +
    coord_equal() + 
    scale_fill_gradientn(colors = c("dark red", "red3", "white", "green3", "dark green"),
      limits=c(-1, 2))

enter image description here

Upvotes: 1

d.b
d.b

Reputation: 32548

d = data.frame(Ticker = as.vector(ticker_matrix),
               Values = as.vector(values_matrix),
               X = as.vector(row(ticker_matrix)),
               Y = as.vector(col(ticker_matrix)))

ggplot(data = d,
       mapping = aes(x = factor(X),
                     y = factor(Y),
                     fill = factor(Values),
                     label = Ticker)) +
    geom_tile(color = "white") +
    geom_text() +
    coord_equal()

enter image description here

If you want to remove axes and legends, check out the answers here.

Upvotes: 3

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