sTrainology {supraHex} | R Documentation

## Function to define trainology (training environment)

### Description

`sTrainology` is supposed to define the train-ology (i.e., the training environment/parameters). The trainology here refers to the training algorithm, the training stage, the stage-specific parameters (alpha type, initial alpha, initial radius, final radius and train length), and the training neighbor kernel used. It returns an object of class "sTrain".

### Usage

    sTrainology(sMap, data, algorithm = c("batch", "sequential"),
    stage = c("rough", "finetune", "complete"), alphaType = c("invert",
    "linear", "power"), neighKernel = c("gaussian", "bubble",
    "cutgaussian", "ep", "gamma"))

### Arguments

`sMap` | an object of class "sMap" or "sInit"
`data` | a data frame or matrix of input data
`algorithm` | the training algorithm. It can be one of "sequential" and "batch" algorithm
`stage` | the training stage. The training can be achieved using two stages (i.e., "rough" and "finetune") or one stage only (i.e., "complete")
`alphaType` | the alpha type. It can be one of "invert", "linear" and "power" alpha types
`neighKernel` | the training neighbor kernel. It can be one of "gaussian", "bubble", "cutgaussian", "ep" and "gamma" kernels

### Value

an object of class "sTrain", a list with following components:

- `algorithm`: the training algorithm

- `stage`: the training stage

- `alphaType`: the alpha type

- `alphaInitial`: the initial alpha

- `radiusInitial`: the initial radius

- `radiusFinal`: the final radius

- `neighKernel`: the neighbor kernel

- `call`: the call that produced this result

### Note

Training stage-specific parameters:

- "radiusInitial": it depends on the grid shape and training stage

  - For "sheet" shape: it equals max(1,ceiling(max(xdim,ydim)/8)) at "rough" or "complete" stage, and max(1,ceiling(max(xdim,ydim)/32)) at "finetune" stage

  - For "suprahex" shape: it equals max(1,ceiling(r/2)) at "rough" or "complete" stage, and max(1,ceiling(r/8)) at "finetune" stage

- "radiusFinal": it depends on the training stage

  - At "rough" stage, it equals radiusInitial/4

  - At "finetune" or "complete" stage, it equals 1

- "trainLength": how many times the whole input data are set for training. It depends on the training stage and training algorithm

  - At "rough" stage, it equals max(1,10 * trainDepth)

  - At "finetune" stage, it equals max(1,40 * trainDepth)

  - At "complete" stage, it equals max(1,50 * trainDepth)

  - When using "batch" algorithm and the trainLength equals 1 according to the above equation, the trainLength is forced to be 2 unless radiusInitial equals radiusFinal

  - Where trainDepth is the training depth, defined as nHex/dlen, i.e., how many hexagons/rectanges are used per the input data length (here dlen refers to the number of rows)

### See Also

`sInitial`

### Examples

    # 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) define trainology at different stages
    # 4a) define trainology at "rough" stage
    sT_rough <- sTrainology(sMap=sI, data=data, stage="rough")
    # 4b) define trainology at "finetune" stage
    sT_finetune <- sTrainology(sMap=sI, data=data, stage="finetune")
    # 4c) define trainology using "complete" stage
    sT_complete <- sTrainology(sMap=sI, data=data, stage="complete")

[Package supraHex version 1.24.0 Index]