GridOperator_Fn: Calculate movement operators on a grid

In James-Thorson/movement_tools: Tools for movement operators in GMRF models

Usage

GridOperator_Fn(grid_dataframe)

Arguments

grid_dataframe

Examples

##---- 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 (grid_dataframe) 
{
    ngrid <- nrow(grid_dataframe)
    h <- 1/sqrt(ngrid)
    nablaxx <- Laplacian_GridOperator("x", grid_dataframe, h = h)
    nablayy <- Laplacian_GridOperator("y", grid_dataframe, h = h)
    gradx <- Diff_GridOperator("x", grid_dataframe, h = h)
    grady <- Diff_GridOperator("y", grid_dataframe, h = h)
    nablaxy <- gradx %*% grady
    gradx_lwr = gradx_upr = gradx
    gradx_lwr[upper.tri(gradx, diag = TRUE)] = 0
    gradx_upr[lower.tri(gradx, diag = TRUE)] = 0
    diag(gradx_upr) = -colSums(gradx_upr)
    diag(gradx_lwr) = -colSums(gradx_lwr)
    grady_lwr = grady_upr = grady
    grady_lwr[upper.tri(grady, diag = TRUE)] = 0
    grady_upr[lower.tri(grady, diag = TRUE)] = 0
    diag(grady_upr) = -colSums(grady_upr)
    diag(grady_lwr) = -colSums(grady_lwr)
    Return = list(nablaxx = nablaxx, nablayy = nablayy, nablaxy = nablaxy, 
        gradx = gradx, grady = grady, gradx_lwr = gradx_lwr, 
        gradx_upr = gradx_upr, grady_lwr = grady_lwr, grady_upr = grady_upr)
    return(Return)
  }

James-Thorson/movement_tools documentation built on May 7, 2019, 10:19 a.m.