# sNeighDirect: Function to calculate direct neighbors for each... In supraHex: supraHex: a supra-hexagonal map for analysing tabular omics data

## Description

`sNeighDirect` is supposed to calculate direct neighbors for each hexagon/rectangle in a regular 2D grid. It returns a matrix with rows for the self, and columns for its direct neighbors.

## Usage

 `1` ```sNeighDirect(sObj) ```

## Arguments

 `sObj` an object of class "sTopol" or "sInit" or "sMap"

## Value

• `dNeigh`: a matrix of nHex x nHex, containing presence/absence info in terms of direct neighbors, where nHex is the total number of hexagons/rectanges in the grid

## Note

The return matrix has rows for the self, and columns for its direct neighbors. The "1" means the presence of direct neighbors, "0" for the absence. It has rows/columns ordered in the same order as the "coord" matrix of the input object does.

`sHexDist`
 ``` 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15``` ```# 1) generate an iid normal random matrix of 100x10 data <- matrix( rnorm(100*10,mean=0,sd=1), nrow=100, ncol=10) # 2) from this input matrix, determine nHex=5*sqrt(nrow(data))=50, # but it returns nHex=61, via "sHexGrid(nHex=50)", to make sure a supra-hexagonal grid sTopol <- sTopology(data=data, lattice="hexa", shape="suprahex") # 3) initialise the codebook matrix using "uniform" method sI <- sInitial(data=data, sTopol=sTopol, init="uniform") # 4) calculate direct neighbors based on different objects # 4a) based on an object of class "sTopol" dNeigh <- sNeighDirect(sObj=sTopol) # 4b) based on an object of class "sMap" # dNeigh <- sNeighDirect(sObj=sI) ```