load(data.filt_推文1.rdata)#Samplesexgenes.file="data/results/genes.table.csv"##创建这个值##非常高级的条件语句，从不同的途径获得基因文件if(!file.exists(genes.file)){#如果没有，就首先从biomart下载suppressMessages(require(biomaRt))#initializeconnectiontomart,maytakesometimeifthesitesare#unresponsive.#下载的数据库和数据集mart-useMart("ENSEMBL_MART_ENSEMBL",dataset="hsapiens_gene_ensembl")#fetchchromosomeinfoplussomeotherannotations#具体下载那些变量genes.table-try(biomaRt::getBM(attributes=c("ensembl_gene_id","external_gene_name","description","gene_biotype","chromosome_name","start_position"),mart=mart,useCache=F))#创建文件夹if(!dir.exists("data/results")){dir.create("data/results")}if(is.data.frame(genes.table)){write.csv(genes.table,file=genes.file)}#如果没下载下来，从这下if(!file.exists(genes.file)){download.file("