# mvsnpdf: multivariate Skew-Normal probability density function In NPflow: Bayesian Nonparametrics for Automatic Gating of Flow-Cytometry Data

 mvsnpdf R Documentation

## multivariate Skew-Normal probability density function

### Description

multivariate Skew-Normal probability density function

### Usage

``````mvsnpdf(x, xi, sigma, psi, Log = TRUE)
``````

### Arguments

 `x` p x n data matrix with n the number of observations and p the number of dimensions `xi` mean vector or list of mean vectors (either a vector, a matrix or a list) `sigma` variance-covariance matrix or list of variance-covariance matrices (either a matrix or a list) `psi` skew parameter vector or list of skew parameter vectors (either a vector, a matrix or a list) `Log` logical flag for returning the log of the probability density function. Defaults is `TRUE`.

`mvnpdf`, `mmvsnpdfC`

### Examples

``````
mvnpdf(x=matrix(1.96), mean=0, varcovM=diag(1), Log=FALSE)
dnorm(1.96)
mvsnpdf(x=matrix(rep(1.96,1), nrow=1, ncol=1),
xi=c(0), psi=c(0), sigma=diag(1),
Log=FALSE
)

mvsnpdf(x=matrix(rep(1.96,2), nrow=2, ncol=1),
xi=c(0, 0), psi=c(1, 1), sigma=diag(2)
)

N=50000#00
Yn <- rnorm(n=N, mean=0, sd=1)

Z <- rtruncnorm(n=N, a=0, b=Inf, mean=0, sd=1)
eps <- rnorm(n=N, mean=0, sd=1)
psi <- 10
Ysn <- psi*Z + eps

nu <- 1.5
W <- rgamma(n=N, shape=nu/2, rate=nu/2)
Yst=Ysn/sqrt(W)

library(reshape2)
library(ggplot2)
data2plot <- melt(cbind.data.frame(Ysn, Yst))
#pdf(file="ExSNST.pdf", height=5, width=4)
p <- (ggplot(data=data2plot)
+ geom_density(aes(x=value, fill=variable, alpha=variable), col="black")#, lwd=1.1)
+ theme_bw()
+ xlim(-15,100)
+ theme(legend.position="bottom")
+ scale_fill_manual(values=alpha(c("#F8766D", "#00B0F6"),c(0.2,0.45)),
name =" ",
labels=c("Y~SN(0,1,10)      ", "Y~ST(0,1,10,1.5)")
)
+ scale_alpha_manual(guide=FALSE, values=c(0.25, 0.45))
+ xlab("Y")
+ ylim(0,0.08)
+ ylab("Density")
+ guides(fill = guide_legend(override.aes = list(colour = NULL)))
+ theme(legend.key = element_rect(colour = "black"))
)
p
#dev.off()

``````

NPflow documentation built on May 29, 2024, 6:04 a.m.