Annotation of OpenXM/src/R/r-packages/hgm/man/hgm.cwishart.Rd, Revision 1.3
1.3 ! takayama 1: % $OpenXM: OpenXM/src/R/r-packages/hgm/man/hgm.cwishart.Rd,v 1.2 2013/03/01 05:27:08 takayama Exp $
1.1 takayama 2: \name{hgm.cwishart}
3: \alias{hgm.cwishart}
4: %- Also NEED an '\alias' for EACH other topic documented here.
5: \title{
6: The function hgm.cwishart evaluates the cumulative distribution function
7: of random wishart matrix.
8: }
9: \description{
10: The function hgm.cwishart evaluates the cumulative distribution function
11: of random wishart matrix of size m times m.
12: }
13: \usage{
1.3 ! takayama 14: hgm.cwishart(m,n,beta,x0,approxdeg,h,dp,x,mode,method,err)
1.1 takayama 15: }
16: %- maybe also 'usage' for other objects documented here.
17: \arguments{
1.2 takayama 18: \item{m}{The dimension of the Wishart matrix.}
19: \item{n}{The degree of freedome (a parameter of the Wishart distribution)}
1.3 ! takayama 20: \item{beta}{The eigenvalues of the inverse of the covariant matrix /2
! 21: (a parameter of the Wishart distribution).
! 22: The beta is equal to inverse(sigma)/2.
1.1 takayama 23: }
1.2 takayama 24: \item{x0}{The point to evaluate the matrix hypergeometric series. x0>0}
1.1 takayama 25: \item{approxdeg}{
1.2 takayama 26: Zonal polynomials upto the approxdeg are calculated to evaluate
27: values near the origin. A zonal polynomial is determined by a given
28: partition (k1,...,km). We call the sum k1+...+km the degree.
1.1 takayama 29: }
30: \item{h}{
1.2 takayama 31: A (small) step size for the Runge-Kutta method. h>0.
1.1 takayama 32: }
33: \item{dp}{
1.2 takayama 34: Sampling interval of solutions by the Runge-Kutta method.
35: }
36: \item{x}{
1.3 ! takayama 37: The second value y[0] of this function is the Prob(L1 < x)
1.2 takayama 38: where L1 is the first eigenvalue of the Wishart matrix.
1.1 takayama 39: }
1.3 ! takayama 40: \item{mode}{
! 41: When mode=c(1,0,0), it returns the evaluation
! 42: of the matrix hypergeometric series and its derivatives at x0.
! 43: When mode=c(1,1,(m^2+1)*p), intermediate values of P(L1 < x) with respect to
! 44: p-steps of x are also returned. Sampling interval is controled by dp.
! 45: }
! 46: \item{method}{
! 47: rk4 is the default value.
! 48: When method="a-rk4", the adaptive Runge-Kutta method is used.
! 49: Steps are automatically adjusted by err.
! 50: }
! 51: \item{err}{
! 52: When err=c(e1,e2), e1 is the absolute error and e2 is the relative error.
! 53: As long as NaN is not returned, it is recommended to set to
! 54: err=c(0.0, 1e-10), because initial values are usually very small.
! 55: }
1.1 takayama 56: }
57: \details{
1.2 takayama 58: It is evaluated by the Koev-Edelman algorithm when x is near the origin and
59: by the HGM when x is far from the origin.
1.3 ! takayama 60: We can obtain more accurate result when the variables h is smaller,
! 61: x0 is relevant value (not very big, not very small),
1.2 takayama 62: and the approxdeg is more larger.
1.3 ! takayama 63: A heuristic method to set parameters x0, h, approxdeg properly
! 64: is to make x larger and to check if the y[0] approaches to 1.
1.1 takayama 65: % \code{\link[RCurl]{postForm}}.
66: }
67: \value{
1.3 ! takayama 68: The output is x, y[0], ..., y[2^m] in the default mode,
1.2 takayama 69: y[0] is the value of the cumulative distribution
70: function P(L1 < x) at x. y[1],...,y[2^m] are some derivatives.
71: See the reference below.
1.1 takayama 72: }
73: \references{
1.2 takayama 74: H.Hashiguchi, Y.Numata, N.Takayama, A.Takemura,
75: Holonomic gradient method for the distribution function of the largest root of a Wishart matrix
76: \url{http://arxiv.org/abs/1201.0472},
1.1 takayama 77: }
78: \author{
79: Nobuki Takayama
80: }
81: \note{
82: %% ~~further notes~~
83: }
84:
85: %% ~Make other sections like Warning with \section{Warning }{....} ~
86:
87: \seealso{
88: %%\code{\link{oxm.matrix_r2tfb}}
89: }
90: \examples{
91: ## =====================================================
1.3 ! takayama 92: ## Example 1.
1.1 takayama 93: ## =====================================================
94: hgm.cwishart(m=3,n=5,beta=c(1,2,3),x=10)
1.3 ! takayama 95: ## =====================================================
! 96: ## Example 2.
! 97: ## =====================================================
! 98: b<-hgm.cwishart(m=4,n=10,beta=c(1,2,3,4),x0=1,x=10,approxdeg=20,mode=c(1,1,(16+1)*100));
! 99: c<-matrix(b,ncol=16+1,byrow=1);
! 100: #plot(c)
1.1 takayama 101: }
102: % Add one or more standard keywords, see file 'KEYWORDS' in the
103: % R documentation directory.
104: \keyword{ Cumulative distribution function of random wishart matrix }
105: \keyword{ Holonomic gradient method }
106: \keyword{ HGM }
107:
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