creating an animated line graph using Plotly package

Question

I'm new to using the plotly package in R and want to animate a line graph. An example would be if I were plotting the GDPpercapita(x-axis) and Life Expectancy (y-axis) of one country. plotly book for R

data(gapminder, package = "gapminder")
    gg <- ggplot(gapminder, aes(gdpPercap, lifeExp, color = continent)) +
    geom_point(aes(size = pop, frame = year, ids = country)) +
    scale_x_log10()
    ggplotly(gg)

I tried creating an ordinary line graph with plotly and adding the frame argument (frame=~year) but the graph is blank.

How can I use Plotly's animation capability to animate a line graph?

Also gganimate is not an option for me as there seems to be a problem with running ImageMagick on Windows.

Answer 1

Here is an animated line graph - interpolating between sine curves of ever increasing periodicity (a dubious thing to do perhaps, but it does look cool).

Here is the code:

# Create a data frame with 10 sine curves with period of 1 to 10
# ranging over a set of points ranging from -pi to +pi

pdf <- NULL
for (p in 1:10){
   x <- pi*(-100:100)/100
   y <- sin(x*p)
   df <- data.frame(x,y,p)
   pdf <- rbind(pdf,df)
}

# now plot it with the animation control "frame" set to "p"

plt <- plot_ly(pdf, x = ~x, y = ~y, frame=~p, type = 'scatter', mode = 'lines')
plt

And here is what it looks like at the start of the animation (frame 1):