I am using the R programming language. I am trying to follow this tutorial (scatterplot3d: regression plane with residuals) and add a "plane" to a scatterplot.

Suppose I have the following data:

```
my_data <- data.frame(read.table(header=TRUE,
row.names = 1,
text="
weight height age
1 2998.958 15.26611 53
2 3002.208 18.08711 52
3 3008.171 16.70896 49
4 3002.374 17.37032 55
5 3000.658 18.04860 50
6 3002.688 17.24797 45
7 3004.923 16.45360 47
8 2987.264 16.71712 47
9 3011.332 17.76626 50
10 2983.783 18.10337 42
11 3007.167 18.18355 50
12 3007.049 18.11375 53
13 3002.656 15.49990 42
14 2986.710 16.73089 47
15 2998.286 17.12075 52
"))
```

I adapted the code to fit my example:

```
library(scatterplot3d)
model_1 <- lm(age ~ weight + height, data = my_data)
# scatterplot
s3d <- scatterplot3d(my_data$height, my_data$weight, my_data$age, pch = 19, type = "p", color = "darkgrey",
main = "Regression Plane", grid = TRUE, box = FALSE,
mar = c(2.5, 2.5, 2, 1.5), angle = 55)
# regression plane
s3d$plane3d(model_1, draw_polygon = TRUE, draw_lines = TRUE,
polygon_args = list(col = rgb(.1, .2, .7, .5)))
# overlay positive residuals
wh <- resid(model_1) > 0
s3d$points3d(my_data$height, my_data$weight, my_data$age, pch = 19)
```

**Problem** : However, the "plane" appears to be absent :

Desired Result:

Can someone please show me what I am doing wrong?

Thanks