Polono(VGAM)
Polono()所属R语言包:VGAM
The Poisson Lognormal Distribution
泊松对数正态分布
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Density, and random generation for the Poisson lognormal distribution.
泊松对数正态分布的密度和随机生成的。
用法----------Usage----------
dpolono(x, meanlog = 0, sdlog = 1, bigx = 170, ...)
ppolono(q, meanlog = 0, sdlog = 1,
isOne = 1 - sqrt( .Machine$double.eps ), ...)
rpolono(n, meanlog = 0, sdlog = 1)
参数----------Arguments----------
参数:x, q
vector of quantiles.
向量的位数。
参数:n
number of observations. If length(n) > 1 then the length is taken to be the number required.
若干意见。如果length(n) > 1的长度是所需的数量。
参数:meanlog, sdlog
the mean and standard deviation of the normal distribution (on the log scale). They match the arguments in Lognormal.
的平均值和标准偏差的正态分布(对数刻度)。他们在Lognormal参数相匹配的。
参数:bigx
Numeric. This argument is for handling large values of x and/or when integrate fails. A first order Taylor series approximation [Equation (7) of Bulmer (1974)] is used at values of x that are greater or equal to this argument. For bigx = 10, he showed that the approximation has a relative error less than 0.001 for values of meanlog and sdlog “likely to be encountered in practice”. The argument can be assigned Inf in which case the approximation is not used.
数字。这种说法是x和/或integrate失败时,处理较大的值。一阶泰勒级数近似公式(7)布尔默(1974)]值x大于或等于这样的说法。对于bigx = 10,他表现出近似的相对误差小于0.001的值meanlog和sdlog“在实践中可能会遇到”。该参数可以分配Inf在这种情况下不使用近似。
参数:isOne
Used to test whether the cumulative probabilities have effectively reached unity.
用于测试的累积概率是否有效地达到统一。
参数:...
Arguments passed into integrate.
传递参数到integrate。
Details
详细信息----------Details----------
The Poisson lognormal distribution is similar to the negative binomial in that it can be motivated by a Poisson distribution whose mean parameter comes from a right skewed distribution (gamma for the negative binomial and lognormal for the Poisson lognormal distribution).
泊松对数正态分布是类似的,因为它可以被激励的泊松分布,其平均参数来自一个右偏态分布(负二项式和对数正态分布的泊松对数正态分布的伽马值)负二项式。
值----------Value----------
dpolono gives the density, ppolono gives the distribution function, and rpolono generates random deviates.
dpolono给出了密度,ppolono给出了分布函数,和rpolono随机产生的偏离。
注意----------Note----------
By default, dpolono involves numerical integration that is performed using integrate. Consequently, computations are very slow and numerical problems may occur (if so then the use of ... may be needed). Alternatively, for extreme values of x, meanlog, sdlog, etc., the use of bigx = Inf avoids the call to integrate, however the answer may be a little inaccurate.
默认情况下,dpolono,使用integrate的执行涉及到的数值积分。因此,计算的速度很慢,数值可能会出现问题(如果是这样的话,那么在使用...的可能需要)。另外,对于极端值的x,meanlog,sdlog“等,用bigx = Inf避免调用integrate,但答案可能是一点点不准确的。
For the maximum likelihood estimation of the 2 parameters a VGAM family function called polono, say, has not been written yet.
最大似然估计的参数aVGAM家庭功能称为polono说,还没有被写入尚未。
(作者)----------Author(s)----------
T. W. Yee.
Some anonymous soul kindly wrote <code>ppolono()</code> and
improved the original <code>dpolono()</code>.
参考文献----------References----------
On fitting the Poisson lognormal distribution to species-abundance data. Biometrics, 30, 101–110.
参见----------See Also----------
lognormal, poissonff, negbinomial.
lognormal,poissonff,negbinomial。
实例----------Examples----------
meanlog = 0.5; sdlog = 0.5; yy = 0:19
sum(proby <- dpolono(yy, m = meanlog, sd = sdlog)) # Should be 1[应该是1]
max(abs(cumsum(proby) - ppolono(yy, m = meanlog, sd = sdlog))) # Should be 0[应为0]
## Not run: opar = par(no.readonly = TRUE)[#不运行:opar = PAR(no.readonly = TRUE)]
par(mfrow = c(2, 2))
plot(yy, proby, type = "h", col = "blue", ylab = "P[Y=y]", log = "",
main = paste("Poisson lognormal(m = ", meanlog,
", sdl = ", sdlog, ")", sep = ""))
y = 0:190 # More extreme values; use the approximation and plot on a log scale[更极端的值,使用近似对数标度和图]
(sum(proby <- dpolono(y, m = meanlog, sd = sdlog, bigx = 100))) # Should be 1[应该是1]
plot(y, proby, type = "h", col = "blue", ylab = "P[Y=y] (log)", log = "y",
main = paste("Poisson lognormal(m = ", meanlog,
", sdl = ", sdlog, ")", sep = "")) # Note the kink at bigx[请注意在bigx扭结]
# Random number generation[随机数生成]
table(y <- rpolono(n = 1000, m = meanlog, sd = sdlog))
hist(y, breaks = ((-1):max(y))+0.5, prob = TRUE, border = "blue")
par(opar)
## End(Not run)[#(不执行)]
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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