每行条件循环

时间:2015-07-21 16:40:12

标签: r loops conditional

我想根据这个例子更改此数据集:

 data<- read.table (text="
        V1  V2  V3  V4  V5  V6  V7  V8 
Chr10_247   T   C   CC241=miss  CC332=het   CC37=ref    CC88=ref    CC886=het
Chr10_445   G   T   CC241=ref   CC332=ref   CC37=het    CC88=ref    CC886=het
Chr10_447   A   C   CC241=homo  CC332=homo  CC37=homo   CC88=homo   CC886=homo
Chr10_481   C   T   CC241=ref   CC332=het   CC37=het    CC88=ref    CC886=het
Chr10_517   G   A   CC241=homo  CC332=het   CC37=ref    CC88=homo   CC886=het
Chr10_637   A   G   CC241=het   CC332=ref   CC37=het    CC88=het    CC886=het"
    stringsAsFactors = FALSE,row.names = NULL,header = T)

V1是基因组上的物理位置(Chr10_247),V2是参考基因座,V3是可选基因座,V4,V5,V6,V7,V8是个体。那么,在哪一行,我需要:

例如使用&#34; A&#34;在V2和B在V3

Change *=ref per 2*V2       A   B   AA  - *ref 
Change *=homo per 2*V3      A   B   BB  - *homo
Change *=het per (V2*V3)    A   B   AB  - *hete
Change *=miss per NA        A   B   NA  - *miss

预期结果:

V1  V2  V3  V4  V5  V6  V7  V8
Chr10_247   T   C   NA  TC  TT  TT  TT
Chr10_445   G   T   GG  GG  GT  GG  GT
Chr10_447   A   C   CC  CC  CC  CC  CC
Chr10_481   C   T   CC  CT  CT  CC  CT
Chr10_517   G   A   AA  GA  GG  AA  GA
Chr10_637   A   G   AG  AA  AG  AG  AG

1 个答案:

答案 0 :(得分:1)

这是解决方案的开始,这是一个相对直接格式的数据转换问题。

library(reshape2)


data <- read.table(text="
                   V1  V2  V3  V4  V5  V6  V7 V8
Chr10_247   T   C   CC241=miss  CC332=het   CC37=ref    CC88=ref    CC886=het
                   Chr10_445   G   T   CC241=ref   CC332=ref   CC37=het    CC88=ref    CC886=het
                   Chr10_447   A   C   CC241=homo  CC332=homo  CC37=homo   CC88=homo   CC886=homo
                   Chr10_481   C   T   CC241=ref   CC332=het   CC37=het    CC88=ref    CC886=het
                   Chr10_517   G   A   CC241=homo  CC332=het   CC37=ref    CC88=homo   CC886=het
                   Chr10_637   A   G   CC241=het   CC332=ref   CC37=het    CC88=het    CC886=het",
                   stringsAsFactors = FALSE,row.names = NULL,header = T)

#melt data for easy vectorized operations
m_data <- melt(data, id.vars=c("V1","V2","V3"),variable.name="Individual",value.name="Status")
head(m_data)

#change status to ref, miss, or homo
m_data$true_status <- gsub(".+=","",m_data$Status)

#format strings based on status
m_data$result <- with(m_data, ifelse(true_status=="miss",NA,
                                     ifelse(true_status=="ref", 
                                            sprintf("%s%s",V2, V2),
                                            ifelse(true_status=="homo", 
                                                   sprintf("%s%s",V3,V3),
                                                   sprintf("%s%s", V2,V3)))))

#turn back to wide
res <- dcast(m_data, V1~Individual)

#merge for V2 and V3
res2 <- merge(data[,c("V1","V2","V3")],res,by="V1")

> res2
         V1 V2 V3   V4 V5 V6 V7 V8
1 Chr10_247  T  C <NA> TC TT TT TC
2 Chr10_445  G  T   GG GG GT GG GT
3 Chr10_447  A  C   CC CC CC CC CC
4 Chr10_481  C  T   CC CT CT CC CT
5 Chr10_517  G  A   AA GA GG AA GA
6 Chr10_637  A  G   AG AA AG AG AG
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