Defining outer edge of filled 2d Contour plot in plotly - r

Question

Problem: I am trying to reproduce a round filled 2d contour plot in R using plotly (have tried ggplot2 also but plotly seemed to be easier).
Data: Sample data download link -
https://drive.google.com/file/d/10Mr5yWVReQckPI6TKLY_vzPT8zWiijKl/view?usp=sharing
The data to be plotted for contour is in a column format and typically called z variable, there is x and y data also available for all values of z. A simple dataframe would look like this:
Please ignore the repeat common x and y as I have truncated decimals. The data has about 25000 rows.
Approach: I first use akima package to interpolate z variable values for given x and y to map z in 2d. This makes the z column data fit in a xy grid for 2d plotting and show contours.
Expected outcome:
Code used:
dens <- akima::interp(x = dt$`Xvalue(mm)`,
y = dt$`Yvalue(mm)`,
z = dt$Values,
duplicate = "mean",
xo=seq(min(dt$`Xvalue(mm)`), max(dt$`Xvalue(mm)`), length = 10),
yo=seq(min(dt$`Yvalue(mm)`), max(dt$`Yvalue(mm)`), length = 10))
plot_ly(x = dens$x,
y = dens$y,
z = dens$z,
colors = c("blue","grey","red"),
type = "contour")
Actual outcome:
Help Needed:
To refine edges of the actual outcome plot to something of a close match to the expected outcome image.
Many thanks in advance for your comments and help.

Answer 1

I found that I could increase the grid output z matrix from akima::interp() from default 40x40 to custom using nx and ny input in function.
And then in plot_ly() add contours = list(coloring = 'fill', showlines = FALSE) to hide contour lines to get output close to my expected outcome.
So working code is like this:
dens <- akima::interp(x = dt$`Xvalue(mm)`,
y = dt$`Yvalue(mm)`,
z = dt$Values,
nx = 50,
ny = 50,
duplicate = "mean",
xo=seq(min(dt$`Xvalue(mm)`), max(dt$`Xvalue(mm)`), length = 50),
yo=seq(min(dt$`Yvalue(mm)`), max(dt$`Yvalue(mm)`), length = 50))
plot_ly(x = dens$x,
y = dens$y,
z = dens$z,
colors = c("blue","grey","red"),
type = "contour",
contours = list(coloring = 'fill', showlines = FALSE))
Plotly contour plot reference was very helpful in this case:
https://plot.ly/r/reference/#contour