sl.trackingshot: Create Trackingshot Movie

Description Usage Arguments Note Author(s) Examples

View source: R/sl.trackingshot.R

Description

Creates a specified number of temporary images and concatenates them to a video. SEE NOTE 1) BELOW FOR A WORKAROUND FOR AN EXISTING ISSUE.

Usage

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sl.trackingshot(way, num, lon, lat, elem, 
  fps = 25L, time = NA, ffmpeg = Sys.which("ffmpeg"), 
  col.background = "white", col.fill = "colbar", col.border = "colbar", 
  colbar = sl.colbar.redgreyblue_256, colbar.breaks = NA, 
  border.lwd = 0.01, border.lty = 1, out.path = getwd(), file.name = "sl.trackingshot.mp4", 
  width = 1080, threads = 1, delete.images = TRUE, verbose = TRUE)

Arguments

way

list of class sl.way like the one returned by sl.trackingshot.way

num, lon, lat, elem

Corresponding argument to sl.plot.field.elem

fps

scalar representing the video's frames per second. Must be greater than 0.

time

Scalar or NA. If NA the way's times will be used, otherwise it will be stretched to time's size.

ffmpeg

String. Path to ffmpeg executable.

col.background

Image background

col.fill

Fill color for polygons

col.border

Polygon border color

colbar

List containing color codes.

colbar.breaks
border.lwd

Border line width

border.lty

Border line type

out.path

Output path for the video file (and the folder with the temporary images)

file.name

File name for the video file

width

Base width for all images in pixels

threads

Thread count to use for creating images

delete.images

Logical value indicating if produced images should be deleted after the video is created

verbose

Logical value indicating whether additional info is printed

Note

1) It appears that the function fails if it's immediately executed with multiple threads. This can be circumvented by starting the function with a single thread, aborting it (if more threads are desired), and re-running it with multiple threads.

2) This initial implementation of the function is designed to make movies based on one specific plotting function, namely sl.plot.field.elem. For the future it would be nice to make this tool more general. For example, the trackingshot function could take a function containing arbitrary plot calls as an argument. The user could then define such a function quite generally, e.g., adding coastlines, points, or whatsoever. Ideally, it should also be possible to use data with a time dimension, so that not only the view is changing but at the same time the displayed field advances in time.

Author(s)

Lukas M<c3><bc>ller, slightly modified by Helge Goessling

Examples

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## Not run: 
### read mesh
mesh = sl.grid.readFESOM(griddir="somedir",rot=TRUE,rot.invert=TRUE,rot.abg=c(50,15,-90))
# a sample mesh can be obtained from GitHub, e.g., using 'svn checkout' from the command line:
# > svn checkout https://github.com/FESOM/FESOM-data/trunk/pi-grid ~/pi-grid

### read corresponding data
require(ncdf4)
dat.file = nc_open(filename="somecorrespondingdata.nc")
dat = ncvar_get(nc=dat.file)
nc_close(nc=dat.file)

### define projection and way
projection = "polar"
p1 = sl.trackingshot.waypoint(projection = projection, time = 1, polar.lonlatrot = c(0,90,0), polar.latbound = 0)
p2 = sl.trackingshot.waypoint(projection = projection, time = 1, polar.lonlatrot = c(15,50,0), polar.latbound = 20)
p3 = sl.trackingshot.waypoint(projection = projection, time = 1, polar.lonlatrot = c(-60,-30,0), polar.latbound = 60)
p4 = sl.trackingshot.waypoint(projection = projection, time = 1, polar.lonlatrot = c(100,40,0), polar.latbound = 20)
p5 = p1
p5$time = 0
points = sl.trackingshot.waypoints(projection = projection, p1, p2, p3, p4, p5)
way = sl.trackingshot.way(waypoints = points, times = c(5,5,5,5))

### make video
sl.trackingshot(way = way, num = dat, lon = mesh$lon, lat=mesh$lat, elem=mesh$elem, fps = 30L, width = 1920, threads = 3, file.name = paste0("~/video_", projection, ".mp4"))

## End(Not run)

helgegoessling/spheRlab documentation built on Sept. 29, 2017, 6:36 a.m.