生存分析过滤报错：Error in if (class(survivalTab1) == "matrix") { : the condition has length > 1

用R包做生存分析滤过，报错如下：

Error in if (class(survivalTab1) == "matrix") { : 
  the condition has length > 1

求高人指路。

下面是R的全部代码：

> setwd("C:\\Users\\Lenovo\\Desktop\\CGGA Practice\\05.survivalFilter")                        #工作目录（需修改）
> pFilter=0.001                                                                #显著性过滤条件
> rt=read.table("expTime.txt",header=T,sep="\t",check.names=F,row.names=1)     #读取输入文件
> rt$futime=rt$futime/365 
> outTab=data.frame()
> sigGenes=c("futime","fustat")
> for(gene in colnames(rt[,3:ncol(rt)])){
+    if(sd(rt[,gene])<0.1){
+      next}
+    a=rt[,gene]<=median(rt[,gene])
+   
+  rt1=rt[a,]
+    b=setdiff(rownames(rt),rownames(rt1))
+    rt2=rt[b,]
+    surTab1=summary(survfit(Surv(futime, fustat) ~ 1, data = rt1))
+    surTab2=summary(survfit(Surv(futime, fustat) ~ 1, data = rt2))
+    survivalTab1=cbind(time=surTab1$time, surv=surTab1$surv,lower=surTab1$lower,upper=surTab1$upper)
+    survivalTab1=survivalTab1[survivalTab1[,"time"]<5,]
+    if(class(survivalTab1)=="matrix"){
+      survivalTab1=survivalTab1[nrow(survivalTab1),]
+    }
+    survivalTab2=cbind(time=surTab2$time, surv=surTab2$surv,lower=surTab2$lower,upper=surTab2$upper)
+    survivalTab2=survivalTab2[survivalTab2[,"time"]<5,]
+    if(class(survivalTab2)=="matrix"){
+      survivalTab2=survivalTab2[nrow(survivalTab2),]
+    }
+    fiveYearsDiff=abs(survivalTab1["surv"]-survivalTab2["surv"])
+ 
+    diff=survdiff(Surv(futime, fustat) ~a,data = rt)
+    pValue=1-pchisq(diff$chisq,df=1)
+    fit=survfit(Surv(futime, fustat) ~ a, data = rt)
+    cox=coxph(Surv(futime, fustat) ~ rt[,gene], data = rt)
+    coxSummary = summary(cox)
+    coxP=coxSummary$coefficients[,"Pr(>|z|)"]
+ 
+    if((pValue<pFilter) & (coxP<pFilter) & (fiveYearsDiff>0.2)){
+        sigGenes=c(sigGenes,gene)
+        outTab=rbind(outTab,
+                    cbind(gene=gene,
+                          KM=pValue,
+                          HR=coxSummary$conf.int[,"exp(coef)"],
+                          HR.95L=coxSummary$conf.int[,"lower .95"],
+                          HR.95H=coxSummary$conf.int[,"upper .95"],
+                      coxPvalue=coxP) )
+  }
+ }
Error in if (class(survivalTab1) == "matrix") { : 
  the condition has length > 1
> write.table(outTab,file="survival.xls",sep="\t",row.names=F,quote=F)    #输出基因和p值表格文件
> surSigExp=rt[,sigGenes]
> surSigExp=cbind(id=row.names(surSigExp),surSigExp)
> write.table(surSigExp,file="surSigExp.txt",sep="\t",row.names=F,quote=F)

查了一些方案说是可以用ifelse语法，但本人是R小白。。不吝赐教。

代码不能照搬运行，检查一下数据格式是不是合要求的。确保分组信息是01分组，其次前两列是生存数据，第三列起是分组信息

楼主解决了吗，我也遇到相同的问题了

楼主解决了吗，我也遇到相同的问题了