index_offset: Find indices of neighbouring nodes

In GJMeijer/soilmech: R functions and plots for Soil Mechanics teaching

Find indices of neighbouring nodes

Description

Find indices of neighbouring nodes in a rectangular grid with or without ghost nodes. Nodes are numbered row-wise. Function assumes that these nodes exist, e.g. no check is conducted to see if this is so...

Usage

index_offset(i, nx, ny, dix = 0, diy = 0, i0 = 0, real_only = FALSE, ...)

Arguments

i	array with node indices
nx	number of real nodes in x and y directions
ny	number of real nodes in x and y directions
dix, diy	index offsets in x and y-directions
i0	node index offset
real_only	if 'TRUE', only real nodes are numbered and ghost nodes are ignored in numbering
...	additional arguments to pass

Value

a list of indices of neightbouring nodes

Examples

nx <- 4
ny <- 3
i <- c(1, 11, 20)
index_offset(i, nx, ny, dix = 1)
index_offset(i, nx, ny, diy = 1)

GJMeijer/soilmech documentation built on May 22, 2022, 10:39 a.m.