voss2g(Voss)
voss2g()所属R语言包：Voss
Fractal Brownian function on 2D grid with a generic Voss algorithm
分形布朗功能与通用沃斯算法的二维网格
译者：生物统计家园网 机器人LoveR
描述----------Description----------
voss2g() function generates realizations of a fractal Brownian function on uniform 2D grid (FBF(x,y)) with a generic version of the Voss algorithm (random sequential additions).
voss2g()函数生成的分形布朗统一的二维网格（FBF（X，Y））的的沃斯算法（随机顺序增加）的一个仿制版本的功能的实现。
用法----------Usage----------
voss2g(p=cbind(n=0.5^-seq(0,7)+1,
s=dchisq(seq(0,7), df=2)),
center=TRUE)
参数----------Arguments----------
参数：p
a matrix of parameters:<br> nrow(p) a number of iterations;<br> p[,"n"] a number of partition points in the iteration process;<br> p[,"s"] a standard deviation of normal pseudorandom additions;
参数的矩阵：<br>文章nrow(p)迭代次数; <br>文章p[,"n"]在迭代过程中的分割点; <br>文章p[,"s"]一个标准偏差的一些正常的伪随机补充;
参数：center
logical; if center=TRUE then the y-coordinates of prefractal points will be centered.
逻辑，如果center=TRUE然后y坐标prefractal点将会集中。
Details
详细信息----------Details----------
The Voss algorithm on 2D grid is based on an iterative partitioning of the initial domain into smaller subdomains by bilinear interpolation of additional points.
沃斯在二维网格算法的基础上分割成更小的子域的初始域通过双线性插值的附加点的迭代。
At each iteration, all values of the fractal Brownian function get normal pseudorandom additions with zero mean and standard deviation, which depends on the iteration index s[i].
在每次迭代中，所有的分形布朗功能得到正常的伪随机增加值与零均值和标准差，这取决于迭代指数s[i]。
By default, the iterative distribution of standard deviation in the generic version of the Voss algorithm is equal to the probability density of the chi-square distribution with 2 degrees of freedom: s[i] <- dchisq(i, df=2).
默认情况下，迭代等于2个自由度的卡方分布的概率密度分布的标准偏差在沃斯算法的通用版本是：s[i] <- dchisq(i, df=2)。
值----------Value----------
A list of Cartesian coordinates of prefractal points.
prefractal点的直角坐标列表。
（作者）----------Author(s)----------
Pavel V. Moskalev
参考文献----------References----------
Modification of the Voss algorithm for simulation of the internal structure of a porous medium //Technical Physics, Vol.50, No.2 (2005), pp.141-145.
参见----------See Also----------
voss1g, voss2d
voss1g，voss2d
实例----------Examples----------
# Example 1: FBF(x,y) with a s[i]=dchisq(i,df=2)[例1：FBF（X，Y）的一则s [i] = dchisq（I，DF = 2）]
set.seed(20120522)
voss <- voss2g()
image(voss, xlab="x", ylab="y",
main="FBF(x,y) with a s[i]=dchisq(i,df=2)")
contour(voss, levels=0, add=TRUE)
# Example 2: FBF(x,y) with a s[i]=dlnorm(i,sdlog=1)[实施例2：FBF（的x，y）与则s [i] = dlnorm（ⅰ，sdlog = 1）]
set.seed(20120522)
voss <- voss2g(p=cbind(n=0.5^-seq(0,7)+1,
s=dlnorm(seq(0,7), sdlog=1)))
image(voss, xlab="x", ylab="y",
main="FBF(x,y) with a s[i]=dlnorm(i,sdlog=1)")
contour(voss, levels=0, add=TRUE)
# Example 3: FBF(x,y) with a s[i]=df(i,df1=7,df2=7)[实施例3：用则s [i] = df的（ⅰ，DF1 = 7，DF2 = 7 FBF（的x，y））]
set.seed(20120522)
voss <- voss2g(p=cbind(n=0.5^-seq(0,7)+1,
s=df(seq(0,7), df1=7, df2=7)))
image(voss, xlab="x", ylab="y",
main="FBF(x,y) with a s[i]=df(i,df1=5,df2=5)")
contour(voss, levels=0, add=TRUE)
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注：
注1：为了方便大家学习，本文档为生物统计家园网机器人LoveR翻译而成，仅供个人R语言学习参考使用，生物统计家园保留版权。
注2：由于是机器人自动翻译，难免有不准确之处，使用时仔细对照中、英文内容进行反复理解，可以帮助R语言的学习。
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发表于 2012-10-1 16:30:58
