DiceView (version 3.1-3)

roots_mesh: Multi Dimensional Multiple Roots (Zero) Finding, sampled by a mesh

Description

Multi Dimensional Multiple Roots (Zero) Finding, sampled by a mesh

Usage

roots_mesh(
  f,
  vectorized = FALSE,
  intervals,
  mesh.type = "seq",
  mesh.sizes = 11,
  maxerror_f = 1e-07,
  tol = .Machine$double.eps^0.25,
  num_workers = maxWorkers(),
  ...
)

Value

matrix of x, so f(x)=0

Arguments

f

Function (one or more dimensions) to find roots of

vectorized

vectorized f: function, TRUE (use f directly), or wrap in Vectorize.function: FALSE (default args), "lapply", "mclapply", ...

intervals

bounds to inverse in, each column contains min and max of each dimension

mesh.type

function or "unif" or "seq" (default) to preform interval partition

mesh.sizes

number of parts for mesh (duplicate for each dimension if using "seq")

maxerror_f

the maximum error on f evaluation (iterates over uniroot to converge).

tol

the desired accuracy (convergence tolerance on f arg).

num_workers

number of parallel roots finding

...

Other args for f

Examples

roots_mesh(function(x) x-.51, intervals=rbind(0,1),
  num_workers=1)
roots_mesh(function(x) sum(x)-.51, intervals=cbind(rbind(0,1),rbind(0,1)),
  num_workers=1)
roots_mesh(sin,intervals=c(pi/2,5*pi/2),
  num_workers=1)
roots_mesh(f = function(x) sin(pi*x[1])*sin(pi*x[2]),
           intervals = matrix(c(1/2,5/2,1/2,5/2),nrow=2),
           num_workers=1)

r = roots_mesh(f = function(x) (0.25+x[1])^2+(0.5+x[2])^2 - .25,
intervals=matrix(c(-1,1,-1,1),nrow=2), mesh.size=5,
  num_workers=1)
plot(r,xlim=c(-1,1),ylim=c(-1,1))

r = roots_mesh(function(x) (0.5+x[1])^2+(-0.5+x[2])^2+(0.+x[3])^2 - .5,
               mesh.sizes = 11,
               intervals=matrix(c(-1,1,-1,1,-1,1),nrow=2),
               num_workers=1)
scatterplot3d::scatterplot3d(r,xlim=c(-1,1),ylim=c(-1,1),zlim=c(-1,1))

roots_mesh(function(x)exp(x)-1,intervals=c(-1,2),
           num_workers=1)
roots_mesh(function(x)exp(1000*x)-1,intervals=c(-1,2),
           num_workers=1)