CODEWITHSUNDEEP
r3dplotlydata-visualization
stats_noob
stats_noob

Reputation: 5925

Adding Contour Lines to 3D Plots

I am working with the R programming language. I made the following 3 Dimensional Plot using the "plotly" library:

library(dplyr)
library(plotly)

  my_function <- function(x,y) {
    
    final_value = (1 - x)^2 + 100*((y - x^2)^2)
     
    }

input_1 <- seq(-1.5, 1.5,0.1)
input_2 <- seq(-1.5, 1.5,0.1)

z <- outer(input_1, input_2, my_function)

plot_ly(x = input_1, y = input_2, z = z) %>% add_surface()

enter image description here

I am now trying to add "contour lines" to the above plot as shown below: https://plotly.com/r/3d-surface-plots/

enter image description here

I am trying to adapt the code from the "plotly website" to make these contours, but I am not sure how to do this:

Graph 1:

# This might have worked?
fig <- plot_ly(z = ~z) %>% add_surface(
  contours = list(
    z = list(
      show=TRUE,
      usecolormap=TRUE,
      highlightcolor="#ff0000",
      project=list(z=TRUE)
      )
    )
  )
fig <- fig %>% layout(
    scene = list(
      camera=list(
        eye = list(x=1.87, y=0.88, z=-0.64)
        )
      )
  )

enter image description here

Graph 2:

# I don't think this worked?
fig <- plot_ly(
  type = 'surface',
  contours = list(
    x = list(show = TRUE, start = 1.5, end = 2, size = 0.04, color = 'white'),
    z = list(show = TRUE, start = 0.5, end = 0.8, size = 0.05)),
  x = ~x,
  y = ~y,
  z = ~z)
fig <- fig %>% layout(
    scene = list(
      xaxis = list(nticks = 20),
      zaxis = list(nticks = 4),
      camera = list(eye = list(x = 0, y = -1, z = 0.5)),
      aspectratio = list(x = .9, y = .8, z = 0.2)))

fig

enter image description here

Can someone please show me how to correctly adapt these above codes?

Upvotes: 4

Views: 2632

Answers (2)

Waldi
Waldi

Reputation: 41240

You were almost there.
The contours on z should be defined according to min-max values of z:

plot_ly(x = input_1, y = input_2, z = z,
        contours = list(
          z = list(show = TRUE, start = round(min(z),-2),
                                end = round(max(z),-2), 
                                size = 100))) %>% 
        add_surface()

enter image description here

or automatically set by plotly :

plot_ly(x = input_1, y = input_2, z = z,
        colors = 'Oranges',
        contours = list(
          z = list(show = TRUE))) %>% 
  add_surface()

enter image description here

Upvotes: 7

zephryl
zephryl

Reputation: 17204

The contour lines are on your plots, but may not be super visible due to the parameters in the contours.z list. Here's how you can tweak the contour lines to fit your needs:

fig <- plot_ly(z = ~z) %>% add_surface(
  contours = list(
    z = list(
      show = TRUE,
      # project=list(z=TRUE)       # (don't) project contour lines to underlying plane
      # usecolormap = TRUE,        # (don't) use surface color scale for contours
      color = "white",             # set contour color
      width = 1,                   # set contour thickness
      highlightcolor = "#ff0000",  # highlight contour on hover
      start = 0,                   # include contours from z = 0...
      end = 1400,                  # to z = 1400...
      size = 100                   # every 100 units

    )
  )
)

You can draw lines along the other dimensions by passing lists to x or y. (Per follow-up question from OP) you can change the surface color scale using colorscale, either specifying one of the named colorscale options or building your own. Example:

fig <- plot_ly(z = ~z) %>% add_surface(
  colorscale = "Picnic",
  contours = list(
    x = list(show=TRUE, color="#a090b0", width=2, start=0, end=30, size=7.5),
    y = list(show=TRUE, color="#a090b0", width=2, start=0, end=30, size=7.5),
    z = list(show=TRUE, color="#a090b0", width=2, start=0, end=1400, size=300)
  )
)

Upvotes: 6

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