dinucleotideFrequencyTest(Biostrings)
dinucleotideFrequencyTest()所属R语言包:Biostrings
Pearson's chi-squared Test and G-tests for String Position Dependence
Pearson的卡方检验和G-测试字符串中的位置依赖
译者:生物统计家园网 机器人LoveR
描述----------Description----------
Performs Person's chi-squared test, G-test, or William's corrected G-test to determine dependence between two nucleotide positions.
执行人的卡方测试,测试的G-,或威廉的修正的G-测试,以确定两核苷酸位置的依赖。
用法----------Usage----------
dinucleotideFrequencyTest(x, i, j, test = c("chisq", "G", "adjG"),
simulate.p.value = FALSE, B = 2000)
参数----------Arguments----------
参数:x
A DNAStringSet or RNAStringSet object.
一个DNAStringSet或RNAStringSet对象。
参数:i, j
Single integer values for positions to test for dependence.
为阵地,以测试依赖单一的整数值。
参数:test
One of "chisq" (Person's chi-squared test), "G" (G-test), or "adjG" (William's corrected G-test). See Details section.
一个"chisq"卡方检验(人),"G"(G试验),或"adjG"(威廉的修正的G-测试)。见详图。
参数:simulate.p.value
a logical indicating whether to compute p-values by Monte Carlo simulation.
逻辑表明是否通过蒙特卡罗模拟计算p值。
参数:B
an integer specifying the number of replicates used in the Monte Carlo test.
一个整数,指定在蒙特卡洛测试使用复制的数量。
Details
详情----------Details----------
The null and alternative hypotheses for this function are:
此函数的空和替代假说:
H0: positions i and j are independent
Ho:职位i和j是独立的
H1: otherwise
H1的:否则
Let O and E be the observed and expected probabilities for base pair combinations at positions i and j respectively. Then the test statistics are calculated as:
让O和E是碱基对组合位置i和j分别观察和预期的概率。然后测试统计计算公式为:
test="chisq": stat = sum(abs(O - E)^2/E)
test="chisq":STAT = SUM(ABS(海外 - C)^ 2 / E的)
test="G": stat = 2 * sum(O * log(O/E))
test="G":STAT = 2 *总和(o *log(O / E))
test="adjG": stat = 2 * sum(O * log(O/E))/q, where
test="adjG":STAT = 2 *总和(o *log(O / E))/ Q,
Under the null hypothesis, these test statistics are approximately distributed chi-squared(df = ((distinct bases at i) - 1) * ((distinct bases at j) - 1)).
约分布假设下,这些测试统计,卡方(DF =((不同的碱基在i) - 1)*((在j的不同碱基) - 1))。
值----------Value----------
An htest object. See help(chisq.test) for more details.
对象的htest。更多详情,请参阅帮助(chisq.test)。
作者(S)----------Author(s)----------
P. Aboyoun
参考文献----------References----------
"Identifying transcription factor binding sites through Markov chain optimations", Bioinformatics, 18 (Suppl. 2), S100-S109.
"Biometry: The Principle and Practice of Statistics in Biological Research", W.H. Freeman and Company, New York.
"Position dependencies in transcription factor binding sites", Bioinformatics, 23, 933-941.
"Improved Likelihood ratio tests for complete contingency tables", Biometrika, 63, 33-37.
参见----------See Also----------
nucleotideFrequencyAt, XStringSet-class, chisq.test
nucleotideFrequencyAt,XStringSet级,chisq.test
举例----------Examples----------
data(HNF4alpha)
dinucleotideFrequencyTest(HNF4alpha, 1, 2)
dinucleotideFrequencyTest(HNF4alpha, 1, 2, test = "G")
dinucleotideFrequencyTest(HNF4alpha, 1, 2, test = "adjG")
转载请注明:出自 生物统计家园网(http://www.biostatistic.net)。
注:
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