# Animated scatter plot over contour plot

I am trying to add an animated scatter plot over a contour plot. However, the contour plot at the first frame just disappears after I hit Play. Is there a way to keep it during the whole animation? Below is the code.

I found this post dealing with the same issue and they had a solution, but it is in Python. I don’t know how to replicate the solution in R.

Thank you.

``````my.f               <- function(x,y){
-sqrt((x-1)^2 + y^2)
}

f                  <- '-sqrt((x-1)^2 + y^2)'

iter               <- data.frame(x=NA,y=NA,z=NA)
iter[1,c('x','y')] <- c(-2,2)
iter[1,]\$z         <- my.f(x=iter[1,1],y=iter[1,2])

change             <- 1
i                  <- 1

while((abs(change) > .01) & (i < 50)){

var = c(x=iter[i,1],y=iter[i,2]))
i                <- i + 1

iter[i,1:2]      <- iter[i-1,1:2] + 0.1*der
iter[i,]\$z       <- my.f(x=iter[i,1],y=iter[i,2])

change           <- iter[i,]\$z - iter[i-1,]\$z

cat('Iteration :', i, 'Value :', round(iter[i,]\$z,4),'\n')
}

iter
iter\$it <- 1:nrow(iter)

grid     <- expand.grid(x=seq(-5,5,.1),y=seq(-5,5,.1))
grid\$z   <- -((grid[,1] - 1)^2 + grid[,2]^2)^.5

plot_ly(grid,
x = ~x,
y = ~y,
z = ~z,
type = 'contour',
colors = 'YlGnBu',
showscale=FALSE,
reversescale =T) %>%