# R/DiscreteMVDistribution.R In distrEx: Extensions of Package 'distr'

```# are rows of x also rows of y
# if yes, row number is computed
.rowNr <- function(x, y){
x <- as.matrix(x)
y <- as.matrix(y)
if(ncol(x) != ncol(y))
stop("'x' and 'y' have different numbers of columns")
res <- numeric(0)
DistrResolution <- getdistrOption("DistrResolution")
for(i in 1:nrow(x))
for(j in 1:nrow(y))
if(isTRUE(all.equal(x[i,], y[j,], tolerance = DistrResolution)))
res <- c(res, j)
return(res)
}

# Generating function
DiscreteMVDistribution <- function(supp, prob, Symmetry = NoSymmetry()){
if(!is.numeric(supp))
stop("'supp' has to be numeric")
if(!is.matrix(supp)){
supp <- t(as.matrix(supp))
}
if(any(!is.finite(supp)))
stop("inifinite or missing values in supp")
len <- nrow(supp)
if(missing(prob)){
prob <- rep(1/len, len)
}else{
if(len != length(prob))
stop("number of columns of 'supp' != length of 'prob'")
if(any(!is.finite(prob)))
stop("inifinite or missing values in prob")
if(sum(prob) != 1)
stop("sum of 'prob' != 1")
if(!all(prob >= 0))
stop("'prob' contains values < 0")
}
if(any(duplicated(supp))){
warning("collapsing to unique support values")
usupp <- supp[!duplicated(supp),]
ind <- .rowNr(supp, usupp)
prob <- as.vector(tapply(prob, ind, sum))
supp <- usupp
len <- nrow(supp)
}

rfun <- function(n){
ind <- sample(x = 1:len, size = n, replace = TRUE, prob = prob)
return(supp[ind,])
}

dfun <- function(x){
if(is.vector(x)) x <- t(x)
ind <- .rowNr(x, supp)
res <- numeric(nrow(x))
if(length(ind) == 0)
return(res)
else{
p <- prob[ind]
if(length(p) < nrow(x)){
res[ind] <- prob[ind]
return(res)
}else return(p)
}
}

pfun <- function(lower, upper){
if(!is.numeric(lower) || !is.numeric(upper))
stop("'lower' and 'upper' have to be numeric vectors")
if(length(lower) != ncol(supp))
stop("wrong dimension of 'lower'")
if(length(upper) != ncol(supp))
stop("wrong dimension of 'upper'")
ind1 <- apply(t(supp) >= lower, 2, all)
ind2 <- apply(t(supp) <= upper, 2, all)
ind <- ind1 & ind2
sum(prob[ind])
}

lB <- apply(supp,2,function(x) all(x> (-Inf)))
uB <- apply(supp,2,function(x) all(x< Inf))

MVD <- new("DiscreteMVDistribution")
MVD@r <- rfun
MVD@d <- dfun
MVD@p <- pfun
MVD@q <- NULL
MVD@param <- NULL
MVD@img <- EuclideanSpace(dimension = floor(ncol(supp)))
MVD@support <- supp
MVD@.withSim <- FALSE
MVD@.withArith <- FALSE
MVD@.logExact <- TRUE
MVD@.lowerExact <- FALSE
MVD@Symmetry <- Symmetry
MVD@.finSupport <- rbind(lB,uB)

return(MVD)
}

setMethod("support", "DiscreteMVDistribution", function(object) object@support)
setMethod("dim", "DiscreteMVDistribution", function(x)ncol(x@support))
```

## Try the distrEx package in your browser

Any scripts or data that you put into this service are public.

distrEx documentation built on May 2, 2019, 5:16 p.m.