p.spatial(OLIN)
p.spatial()所属R语言包:OLIN
Assessment of the significance of spatial bias based on p-values
空间偏见的重要性评估的基础上p值
译者:生物统计家园网 机器人LoveR
描述----------Description----------
This function assesses the significance of spatial bias. This is achieved by comparing the observed average values of logged fold-changes within a spot's spatial neighbourhood with an empirical distribution generated by permutation tests. The significance is given
此功能评估空间偏见的意义。这是通过比较记录fold change的观测平均值与排列测试所产生的经验分布在一个点的空间邻里。意义
用法----------Usage----------
p.spatial(X,delta=2,N=-1,av="median",p.adjust.method="none")
参数----------Arguments----------
参数:X
matrix of logged fold changes
记录的fold change矩阵
参数:delta
integer determining the size of spot neighbourhoods ((2*delta+1)x(2*delta+1)).
整数确定现货街区的大小((2*delta+1)x(2*delta+1))。
参数:N
number of samples for generation of empirical background distribution
样本数为一代的经验背景分布
参数:av
averaging of M within neighbourhood by mean or median (default)
平均M内邻里均值或中位数(默认)
参数:p.adjust.method
method for adjusting p-values due to multiple testing regime. The available methods are “none”, “bonferroni”, “holm”, “hochberg”, “hommel” and “fdr”. See also p.adjust. </table>
由于多次的测试制度,调整p值的方法。可用的方法是“无”,“邦弗朗尼”,“冬青”,“hochberg”,“HOMMEL”和“FDR”。还可以看p.adjust。 </ TABLE>
Details
详情----------Details----------
The function p.spatial assesses the significance of spatial bias using an one-sided random permutation test. The null hypothesis states random spotting i.e. the independence of log ratio M and spot location. First, a neighbourhood of a spot is defined by a two dimensional square window of chosen size ((2*delta+1)x(2*delta+1)). Next, a test statistic is defined by calculating the median or mean of M for N random samples of size ((2*delta+1)x(2*delta+1)). Note that this scheme defines a sampling with replacement procedure whereas sampling without replacement is used for fdr.spatial. Comparing the empirical distribution of median/mean of \code{M} with the observed distribution of median/mean of \code{M}, the independence of M and spot location can be assessed. If M is independent of spot's location, the empirical distribution can be expected to be distributed around its mean value. To assess the significance of observing positive deviations of median/mean of \code{M}, p-values are calculated using Fisher's method. The p-value equals the fraction of values in the empirical distribution which are larger than the observed value . The minimal p-value is set to 1/N. Correspondingly, the significance of observing negative deviations of median/mean of \code{M} can be determined.
功能p.spatial评估片面的随机排列试验使用空间偏见的意义。空假说,即独立的log比M点位置的随机发现。首先,一个一个点的附近,是指由一个二维选择大小的正方形窗口((2 *Delta+1)×(2 *Delta+1))。接下来,定义一个测试统计计算中位数或等于MN随机样本的大小((2 *Delta+1)×(2 *Delta+1))。请注意,该方案定义了一个与更换过程中的取样,而无需更换采样fdr.spatial。 median/mean of \code{M}与median/mean of \code{M}的观测分布,M点位置的独立性,可以评估的经验分布的比较。 M如果是独立点的位置,可以预期的经验分布,周围分布及其均值。评估观测偏差的积极的意义median/mean of \code{M},p值计算使用费雪的方法。 p值等于经验分布值比实测值大的比例。最小的p值设置为1/N。相应的,意义观察负偏差median/mean of \code{M}的,可确定。
值----------Value----------
A list of vectors containing the p-values for positive (Pp) and negative (Pn) deviations of
含有的P-值(Pp)为积极和消极(Pn)偏差的向量列表
作者(S)----------Author(s)----------
Matthias E. Futschik (<a href="http://itb.biologie.hu-berlin.de/~futschik">http://itb.biologie.hu-berlin.de/~futschik</a>)
参见----------See Also----------
fdr.int, sigxy.plot, p.adjust
fdr.int,sigxy.plot,p.adjust
举例----------Examples----------
# To run these examples, "un-comment" them![要运行这些例子,“联合国发表评论”他们!]
#[]
# LOADING DATA[加载数据]
# data(sw)[数据(SW)]
# M <- v2m(maM(sw)[,1],Ngc=maNgc(sw),Ngr=maNgr(sw),[v2m M“ - (MAM(SW)[1],NGC = maNgc(SW),NGR = maNgr(SW),]
# Nsc=maNsc(sw),Nsr=maNsr(sw),main="MXY plot of SW-array 1")[NSC = maNsc(SW),NSR = maNsr(SW),主要=“SW阵列1 MXY图”)]
#[]
# CALCULATION OF SIGNIFICANCE OF SPOT NEIGHBOURHOODS[作者:现货,邻里意义的计算]
# For this illustration, N was chosen rather small. For "real" analysis, it should be larger.[对于这个例子,N的选择相当小。 “真实”的分析,它应该更大。]
# P <- p.spatial(M,delta=2,N=10000,av="median")[p.spatial,P < - (男,Delta= 2,n = 10000,AV =“中位数”)]
# sigxy.plot(P$Pp,P$Pn,color.lim=c(-5,5),main="FDR")[sigxy.plot($ PP,P $ PN color.lim = C(-5,5),主要=“FDR”)]
# LOADING NORMALISED DATA[装载正规化的资料]
# data(sw.olin)[数据(sw.olin)]
# M <- v2m(maM(sw.olin)[,1],Ngc=maNgc(sw.olin),Ngr=maNgr(sw.olin),[M“ - v2m(MAM(sw.olin)的[1],NGC = maNgc(sw.olin),NGR = maNgr(sw.olin),]
# Nsc=maNsc(sw.olin),Nsr=maNsr(sw.olin),main="MXY plot of SW-array 1")[的NSC = maNsc(sw.olin)(NSR = maNsr sw.olin),主要=“SW阵列1 MXY图”)]
# CALCULATION OF SIGNIFICANCE OF SPOT NEIGHBOURHOODS[作者:现货,邻里意义的计算]
# P <- p.spatial(M,delta=2,N=10000,av="median")[p.spatial,P < - (男,Delta= 2,n = 10000,AV =“中位数”)]
# VISUALISATION OF RESULTS[结果的可视化]
# sigxy.plot(P$Pp,P$Pn,color.lim=c(-5,5),main="FDR")[sigxy.plot($ PP,P $ PN color.lim = C(-5,5),主要=“FDR”)]
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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