How to make a color plot of a matrix in r

Question

The plot between e_values and r_values, the values of probabilities of fp0 indicated by different colors of my color scale. I have a matrix which has 132 rows and 3 columns.The names of the are e_values, r_values and fp0.Now how do I plot a color plot of my matrix?The plot must have e_values on the y-axis and r_values on the x-axis and the various values of fp0 as the colors.The e_values vary from 0 to 0.5 in the intervals of 0.1 and the r_values vary from 0 to 6.5, in the intervals of 0.5 till 4 and then 0.2 from 4 to 6.5 and my fp0 values are basically my probabilities and so they vary from 0 to 1.I couldn't figure out the way to upload my csv file and so I gave a description of my matrix and am also printing my matrix.I am also quite new to R and quite unfamiliar with the way the packages like ggplot2 and similar others work, so it will be very helpful if I get a detailed explanation.

      e_values   r_values   fp0
    1   0          0         1.0000
    2   0.1        0         1.0000
    3   0.2        0         1.0000
    4   0.3        0         1.0000
    5   0.4        0         1.0000
    6   0.5        0         1.0000   
    7   0          0.5       1.0000  
    8   0.1        0.5       1.0000 
    9   0.2        0.5       1.0000
   10   0.3        0.5       1.0000
   11   0.4        0.5       1.0000
   12   0.5        0.5       1.0000
   13   0          1         1.0000

My matrix goes on in the above manner until r=4, after which the subsequent r values increase by 0.2 and the fp0 values also start to show variation. and this pattern is followed till the no. of rows become 132.

Answer 1

You just need to use fp0 as color in your ggplot.

The code below will create the plot you described. Here, darker colors indicate higher probabilities. If you have a discrete probability, you could also use distinct colors for each level (second plot).

require(ggplot2)

e_values = seq(0, 0.5, by = 0.1)
r_values = c(seq(0, 4, by = 0.5), seq(4.2, 6.5, by = 0.2))

df <- data.frame(e_values = sample(e_values, 132, replace = T),
                 r_values = sample(r_values, 132, replace = T),
                 fp0 = runif(132))

g <- ggplot(df, aes(x = r_values, y = e_values, color = fp0))
g <- g + geom_point()
g

df <- data.frame(e_values = sample(e_values, 132, replace = T),
                 r_values = sample(r_values, 132, replace = T),
                 fp0 = sample(seq(0, 1, by = 0.2), 132, replace = T))

g <- ggplot(df, aes(x = r_values, y = e_values, color = as.factor(fp0)))
g <- g + geom_point()
g

Edit: The picture you uploaded has r_values as y axis and e_values as x axis. Additionally, the shape of the points is different. Here is the code to produce the desired plot:

g <- ggplot(df, aes(x = e_values, y = r_values, color = fp0))
g <- g + geom_point(shape = 15, aes(fill = fp0))
g