render_gif generates an error when generated frames are less than the frames argument specified

[huizezhang-sherry]

An error with render_gif():

library(tourr)
set.seed(123)
gif_file <- file.path(tempdir(), "test.gif")
tourr::render_gif(
  flea[1:6],
  tour_path = guided_tour(holes()),
  display = display_xy(),
  frames = 70,
  gif_file = gif_file
)
  
#> Value  0.538   43.4 % better  - NEW BASIS
#> Value  0.730   35.6 % better  - NEW BASIS
#> Value  0.780   6.8 % better  - NEW BASIS
#> Value  0.846   8.5 % better  - NEW BASIS
#> Value  0.872   3.2 % better  - NEW BASIS
#> Value  0.883   1.3 % better  - NEW BASIS
#> Value  0.887   0.4 % better  - NEW BASIS
#> Value  0.891   0.5 % better  - NEW BASIS
#> Value  0.897   0.7 % better  - NEW BASIS
#> Value  0.903   0.7 % better  - NEW BASIS
#> Value  0.906   0.3 % better  - NEW BASIS
#> Value  0.906   0.0 % better 
#> Value  0.910   0.5 % better  - NEW BASIS
#> Value  0.910   0.0 % better 
#> Value  0.912   0.3 % better  - NEW BASIS
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> No better bases found after 25 tries.  Giving up.
#> Final projection: 
#> 0.333  0.486  
#> 0.338  -0.344  
#> 0.412  -0.189  
#> 0.381  -0.337  
#> 0.467  0.644  
#> 0.492  -0.285
#> Error in normalizePath(png_files, mustWork = TRUE): path[61]="/var/folders/_t/v9kjp3yn2k73wm16y_jlphgsbbd6_6/T//Rtmpb5P9kJ/frame061.png": No such file or directory

^{Created on 2022-10-06 by the reprex package (v2.0.1)}

This is because only 60 frames are generated with this guided tour configeration while 70 frames are asked to be rendered. The following uses tourr::render() to validate:

library(tourr)
set.seed(123)
png_files <- file.path(tempdir(), "test-%03d.png")
tourr::render(
  data = flea[,1:6],
  tour_path = guided_tour(holes()),
  display = display_xy(),
  frames = 100, "png",
  png_files)
#> Converting input data to the required matrix format.
#> Value  0.538   43.4 % better  - NEW BASIS
#> Using half_range 0.98
#> Value  0.730   35.6 % better  - NEW BASIS
#> Value  0.780   6.8 % better  - NEW BASIS
#> Value  0.846   8.5 % better  - NEW BASIS
#> Value  0.872   3.2 % better  - NEW BASIS
#> Value  0.883   1.3 % better  - NEW BASIS
#> Value  0.887   0.4 % better  - NEW BASIS
#> Value  0.891   0.5 % better  - NEW BASIS
#> Value  0.897   0.7 % better  - NEW BASIS
#> Value  0.903   0.7 % better  - NEW BASIS
#> Value  0.906   0.3 % better  - NEW BASIS
#> Value  0.906   0.0 % better 
#> Value  0.910   0.5 % better  - NEW BASIS
#> Value  0.910   0.0 % better 
#> Value  0.912   0.3 % better  - NEW BASIS
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.1 % better 
#> Value  0.913   0.0 % better 
#> Value  0.913   0.0 % better 
#> No better bases found after 25 tries.  Giving up.
#> Final projection: 
#> 0.333  0.486  
#> 0.338  -0.344  
#> 0.412  -0.189  
#> 0.381  -0.337  
#> 0.467  0.644  
#> 0.492  -0.285
length(list.files(tempdir()))
#> [1] 60

^{Created on 2022-10-06 by the reprex package (v2.0.1)}