spins: Spin the current rgl window continuously
In p3d: Plot 3d data and fitted surfaces

Description Usage Arguments Details Value Author(s) See Also Examples

Spins the current rgl window with constant increment(s) in theta and/or phi. Use <ESC> in the R window to stop.

1	spins(inc.theta = 1/4, inc.phi = 0, theta = NULL, phi = NULL)

`inc.theta`	Increment for rotation about the vertical, `y`, axis.
`inc.phi`	Increment for rotation around the `x` axis.
`theta`	Initial value for `theta`. By default, the current orientation is used.
`phi`	Initial value for `phi`. By default, the current orientation is used.

TBW

None

Georges Monette

spin, spin3d

##---- Should be DIRECTLY executable !! ----
##-- ==>  Define data, use random,
##--	or do  help(data=index)  for the standard data sets.

## The function is currently defined as
function( inc.theta = 1/4, inc.phi = 0, theta = NULL, phi = NULL) {
 help = "
    Spins the current rgl window with a constant increment in theta and phi.
    Use ESC in R window to stop.
    BUG: - Respects some mouse motions but behaves unpredictably.
         - Should have a better way to stop
 "
      um <- par3d('userMatrix')
      Acos = function(x) 360*acos(x)/(2*pi)
      Asin = function(x) 360*asin(x)/(2*pi)
      Atan2 = function( s, c) atan2( s, c)*(180/pi)
      theta.phi = function( ) {

          par3d()
          um = par3d('userMatrix')
          list(theta = Atan2(-um[1,3], um[1,1]), phi = Atan2 (um[3,2],um[2,2]))
      }

      tp = theta.phi()
      if(is.null(theta)) theta = tp$theta
      if(is.null(phi)) phi = tp$phi
      while(TRUE) {
           theta = (theta + inc.theta) %% 360
           phi = phi + inc.phi
           spin( theta = theta , phi = phi)
           tp = theta.phi()
           # print( tp )
           theta = tp$theta
           phi = tp$phi
      }
      invisible(NULL)
  }