R: "Coloring" plotly plots according to another variable

Question

I am working with the R programming language. I am trying to replicate the answer provided in this Stack Overflow post over here: Color surface by variable with plotly in R

Suppose I have the following "data frame" ("my_grid"):

library(plotly)
library(dplyr)

#create grid and evaluate function
input_1 <- seq(0,100,1)
input_2 <- seq(0,100,1)
input_3 <- seq(0,100,1)
input_4 <- seq(0,100,1)

my_grid <- data.frame(input_1, input_2, input_3, input_4)
my_grid$final_value = sin(input_1) + cos(input_2) + input_3 + input_4

We can see how this data frame looks like:

head(my_grid)

  input_1 input_2 input_3 input_4 final_value
1       0       0       0       0    1.000000
2       1       1       1       1    3.381773
3       2       2       2       2    4.493151
4       3       3       3       3    5.151128
5       4       4       4       4    6.589554
6       5       5       5       5    9.324738

Question: I want to make a 3D surface plot with variables "input_1", "input_2", "input_3" - And then color the surface according to "final_value"

       plot_ly() %>% 
            add_trace(data = my_grid,  x=my_grid$input_1, y=my_grid$input_2, z=my_grid$input_3, type="mesh3d" )
 %>%   add_surface(surfacecolor = my_grid$final_value,
                  cauto=F,
                  cmax=max(my_grid$final_value),
                  cmin=min(my_grid$final_value)
      )

But this returns several errors, such as:

• Error: unexpected SPECIAL in "%>%"
• Error: unexpected ',' in " cauto=F,"

I have tried different ways to debug this code, but I can't seem to figure it out. Can someone please show me how to fix these errors?

Answer 1

I fixed some of your syntax and added z = my_grid %>% as.matrix() to your code, and it works as intended now. See below,

plot_ly() %>% 
        add_trace(data = my_grid,  x=my_grid$input_1, y=my_grid$input_2, z=my_grid$input_3, type='mesh3d') %>%
        add_surface(
                z = my_grid %>% as.matrix(),
                surfacecolor = my_grid,
                cauto=F,
                cmax=max(my_grid$final_value),
                cmin=min(my_grid$final_value)
        )

Your first error were the following,

foo()
%>% bar()

In order for the %>% to work as intended, it has to be inline of ending parenthesis.

When the syntax were corrected, I got the Error: 'z' must be a numeric matrix. And therefore I added z = my_grid %>% as.matrix().

---

Note: If it still doesn't work as intended, please post your sessionInfo(), as the code worked for me after syntax correction and addition of arguments.