designdist(vegan)
designdist()所属R语言包：vegan
Design your own Dissimilarities
设计您自己的四不像
译者：生物统计家园网 机器人LoveR
描述----------Description----------
You can define your own dissimilarities using terms for shared and total quantities, number of rows and number of columns. The shared and total quantities can be binary, quadratic or minimum terms. In binary terms, the shared component is number of shared species, and totals are numbers of species on sites. The quadratic terms are cross-products and sums of squares, and minimum terms are sums of parallel minima and row totals.
你可以定义你自己的相异共享和总数量，行数和列数。共享和总数量可以是二进制，二次或最低刑期。在二进制计算，共享组件是共享的物种数量之和与合计是种网站上的数字。二次项是跨产品和平方和，最低刑期是平行的极小值和行总计金额。
用法----------Usage----------
designdist(x, method = "(A+B-2*J)/(A+B)",
terms = c("binary", "quadratic", "minimum"),
abcd = FALSE, name)
参数----------Arguments----------
参数：x
Input data.
输入数据。
参数：method
Equation for your dissimilarities. This can use terms J for shared quantity, A and B for totals, N for the number of rows (sites) and P for the number of columns (species). The equation can also contain any R functions that accepts vector arguments and returns vectors of the same length.
您的异同方程。 J共享数量，这可以用，A和B总数，N的行数（点）和P的数目列（种）。方程式也可含有任何R函数接受矢量参数和返回相同的长度的矢量。
参数：terms
How shared and total components are found. For vectors x and y the "quadratic" terms are J = sum(x*y), A = sum(x^2), B = sum(y^2), and "minimum" terms are J = sum(pmin(x,y)), A = sum(x) and B = sum(y), and "binary" terms are either of these after transforming data into binary form (shared number of species, and number of species for each row).
如何共享和总成分被发现。的向量x和y"quadratic"条款J = sum(x*y)，A = sum(x^2)，B = sum(y^2)和"minimum"条款<X >，J = sum(pmin(x,y))和A = sum(x)和B = sum(y)条款后，将数据转换为二进制形式（共享的物种数量，种类的每一行）。
参数：abcd
Use 2x2 contingency table notation for binary data: a is the number of shared species, b and c are the numbers of species occurring only one of the sites but not in both, and d is the number of species that occur on neither of the sites.
使用2×2列联表表示为二进制数据：a是共享的物种的数量，b和c发生的物种数量的网站只有一个，但不同时，和 d的网站都不上发生的物种的数量。
参数：name
The name you want to use for your index. The default is to combine the method equation and terms argument.
您要使用的名称为您的索引。默认是method方程和terms参数相结合。
Details
详细信息----------Details----------
Most popular dissimilarity measures in ecology can be expressed with the help of terms J, A and B, and some also involve matrix dimensions N and P. Some examples you can define in designdist are:
在生态可表示最流行的相异措施的帮助条款J，A和B，和一些还涉及到矩阵尺寸N和P。一些例子中，你可以定义在designdist是：
S酶rensen
索伦森
Ru啪i膷ka
鲁齐卡
The function designdist can implement most dissimilarity indices in vegdist or elsewhere, and it can also be used to implement many other indices, amongst them, most of those described in Legendre & Legendre (1998). It can also be used to implement all indices of beta diversity described in Koleff et al. (2003), but there also is a specific function betadiver for the purpose.
可以实现的功能designdist最vegdist或其他地方的差异性指数，它也可以被用来实现许多其他指标，他们当中，大部分在勒让德勒让德（1998）所描述的。它也可以被用于实现beta多样性在Koleff等描述的所有索引。 （2003年），但是也有特定的功能betadiver为宗旨。
If you want to implement binary dissimilarities based on the 2x2 contingency table notation, you can set abcd = TRUE. In this notation a = J, b = A-J, c = B-J, d = P-A-B+J. This notation is often used instead of the more more tangible default notation for reasons that are opaque to me.
如果你想实现二进制异同的基础上的2×2列联表的符号，你可以设置abcd = TRUE。在这个符号a = J，b = A-J，c = B-J，d = P-A-B+J。我是不透明的原因，经常被用来代替此符号的更多有形的默认符号。
值----------Value----------
designdist returns an object of class dist.
designdist返回一个对象类dist。
注意----------Note----------
designdist does not use compiled code, and may be slow or use plenty of memory in large data sets. It is very easy to make errors when defining a function by hand. If an index is available in a function using compiled code, it is better to use the canned alternative.
designdist不使用编译后的代码，可能会很慢，或者使用大量的内存在大型数据集。这是很容易定义一个函数时，使错误的。如果指数是在一个函数中使用编译后的代码，最好是使用罐装的选择。
（作者）----------Author(s)----------
Jari Oksanen
参考文献----------References----------
diversity for presence–absence data. J. Animal Ecol. <STRONG>72</STRONG>, 367–382.
English ed. Elsevier
参见----------See Also----------
vegdist, betadiver, dist.
vegdist，betadiver，dist。
实例----------Examples----------
## Arrhenius dissimilarity: the value of z in the species-area model[＃阿累尼乌斯不同：z的值在种 - 面积模型]
## S = c*A^z when combining two sites of equal areas, where S is the[＃S = C * A ^ Z结合时的面积大致相等的两个网站，其中S是]
## number of species, A is the area, and c and z are model parameters.[＃物种数量，A区，C和Z为模型参数。]
## The A below is not the area (which cancels out), but number of[＃下文A区域（取消），但数量]
## species in one of the sites, as defined in designdist().[＃物种的网站之一，在designdist（）中所定义。]
data(BCI)
dis <- designdist(BCI, "(log(A+B-J)-log(A+B)+log(2))/log(2)")
## This can be used in clustering or ordination...[＃这可以用来在聚类或协调...]
ordiplot(cmdscale(dis))
## ... or in analysing beta diversity (without gradients)[＃...或梯度分析beta多样性（不）]
summary(dis)
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 15:05:22
