making animated breathing gif in #rstats

breath.R

library(ggplot2)
library(dplyr)
library(gganimate)
exhale <- 5 # seconds
exhaled_pause <- 3 # seconds
inhale <- 4 # seconds
inhaled_pause <- 4 # seconds
frames_per_second = 16

exh <- data.frame(stage = rep("exhale", exhale*frames_per_second), 
                  onscreen = rep(paste("exhale", exhale), exhale*frames_per_second),
                  strength = 100*((exhale*frames_per_second):1)/(exhale*frames_per_second),
                  stringsAsFactors = FALSE)
exp <- data.frame(stage = rep("exhaled_pause", exhaled_pause*frames_per_second), 
                  onscreen = rep(paste("pause",exhaled_pause), exhaled_pause*frames_per_second),
                  strength = rep(1,exhaled_pause*frames_per_second),
                  stringsAsFactors = FALSE)
inh <- data.frame(stage = rep("inhale", inhale*frames_per_second), 
                  onscreen = rep(paste("inhale",inhale), inhale*frames_per_second),
                  strength = 100*(1:(inhale*frames_per_second))/(inhale*frames_per_second),
                  stringsAsFactors = FALSE)
inp <- data.frame(stage = rep("inhaled_pause", inhaled_pause*frames_per_second), 
                  onscreen = rep(paste("pause",inhaled_pause), inhaled_pause*frames_per_second),
                  strength = rep(100,inhaled_pause*frames_per_second),
                  stringsAsFactors = FALSE)

gf <- bind_rows(inh, inp, exh, exp) %>% 
  mutate(frame_n = row_number()) %>% 
  ggplot(aes(colour=strength,x=strength)) + geom_point(y=2, size=4) + scale_color_viridis_c() +
  scale_size_identity() + ylim(1,3) + coord_polar() +
  theme_void() + theme(legend.position = "none") + 
  geom_text(aes(label=onscreen),x=0,y=1, size=6, colour="#AAAAAA") +
  transition_states(frame_n, transition_length = 0, state_length = 1) 

animate(gf, nframes =((exhale+exhaled_pause+inhale+inhaled_pause)*frames_per_second),
        fps=frames_per_second)
anim_save("~/Desktop/breath.gif")