R: Transform parameters for linear transformations on response...

LinTransform {IsingSampler} | R Documentation

## Transform parameters for linear transformations on response catagories

### Description

This function is mainly used to translate parameters estimated with response options set to 0 and 1 to a model in which the response options are -1 and 1, but can be used for any linear transformation of response options.

### Usage

    LinTransform(graph, thresholds, from = c(0L, 1L), to = c(-1L, 1L), a, b)

### Arguments

`graph` | A matrix containing an Ising graph
`thresholds` | A vector containing thresholds
`from` | The original response encoding
`to` | The response encoding to transform to
`a` | The slope of the transformation. Overwrites `to`.
`b` | The intercept of the transformation. Overwrites `to`.

### Author(s)

Sacha Epskamp <sacha.epskamp@gmail.com>

### Examples

    N <- 4 # Number of nodes

    # Ising parameters:
    Graph <- matrix(sample(0:1,N^2,TRUE,prob = c(0.7, 0.3)),N,N) * rnorm(N^2)
    Graph <- pmax(Graph,t(Graph)) / N
    diag(Graph) <- 0
    Thresh <- -(rnorm(N)^2)
    Beta <- 1

    p1 <- IsingLikelihood(Graph, Thresh, Beta, c(0,1))

    a <- 2
    b <- -1

    # p2 <- IsingLikelihood(Graph/(a^2), Thresh/a - (b*rowSums(Graph))/a^2, Beta, c(-1,1))

    p2 <- IsingLikelihood(LinTransform(Graph,Thresh)$graph,
                          LinTransform(Graph,Thresh)$thresholds ,
                          Beta, c(-1,1))
    LinTransform

    round(cbind(p1[,1],p2[,1]),5)

    plot(p1[,1],p2[,1])
    abline(0,1)

[Package IsingSampler version 0.2.1 Index]