calling primer3 from R

callPrimer3.R

#' call primer3 for a given set of DNAstringSet object
#'
#' @param seq DNAstring object, one DNA string for the given amplicon
#' @param size_range default: '151-500'
#' @param Tm melting temprature parameters default:c(55,57,58)
#' @param name name of the amplicon in chr_start_end format
#' @param primer3 primer3 location
#' @param therme.param thermodynamic parameters folder
#' @param settings text file for parameters
#' @author Altuna Akalin modified Arnaud Krebs' original function
#' @example
#' 
#' primers=mapply(.callP3NreadOrg,seq=sample.seq,
#'                                   name=names(sample.seq),
#'                      MoreArgs=list(primer3=primer3,size_range=size_range,Tm=Tm,
#'                                    thermo.param=thermoParam,settings=settings)
#'                      ,SIMPLIFY = FALSE)
#' 
#' 
.callP3NreadOrg<-function(seq,size_range='151-500',Tm=c(55,57,58),name,
                       primer3="/work2/gschub/arnaud/softwares/primer3/primer3-2.3.4/bin/primer3_core",
                       thermo.param="/work2/gschub/arnaud/softwares/primer3/primer3-2.3.4/src/primer3_config/",
                       settings="/work2/gschub/arnaud/softwares/primer3/primer3-2.3.4/default_settings.txt"){
  



  #print(excluded.regions)
  # make primer 3 input file
  p3.input=tempfile()
  p3.output=tempfile()
  write(
    paste( sprintf("SEQUENCE_ID=%s\n",name  ),
           sprintf("SEQUENCE_TEMPLATE=%s\n",as.character(seq),
           "PRIMER_TASK=pick_detection_primers\n",
           "PRIMER_PICK_LEFT_PRIMER=1\n" ,
           "PRIMER_PICK_INTERNAL_OLIGO=0\n",
           "PRIMER_PICK_RIGHT_PRIMER=1\n"  ,
           "PRIMER_EXPLAIN_FLAG=1\n"  ,
           "PRIMER_PAIR_MAX_DIFF_TM=3\n",
           sprintf("PRIMER_MIN_TM=%s\n" ,Tm[1]),
           sprintf("PRIMER_OPT_TM=%s\n" ,Tm[2]),
           sprintf("PRIMER_MAX_TM=%s\n" ,Tm[3]),
           sprintf("PRIMER_PRODUCT_SIZE_RANGE=%s\n" ,size_range),
           
           sprintf("PRIMER_THERMODYNAMIC_PARAMETERS_PATH=%s\n" ,thermo.param),
           "=",
           sep=''
    )
    ,
    p3.input
  )
  #call primer 3 and store the output in a temporary file
  
  try(system(
    paste(primer3 ,p3.input, "-p3_settings_file",settings, 
                ">", p3.output)
  ))
  
  #import and parse the output into a dataframe named designed.primers
  out=read.delim(p3.output, sep='=', header=FALSE)
  
  unlink(c(p3.input,p3.output) ) # delete temp files
  returned.primers=as.numeric(as.vector(out[out[,1]=='PRIMER_PAIR_NUM_RETURNED',][,2]))
  if (length(returned.primers)==0){ warning('primers not detected for ',name,call. = FALSE);return(NA)}
  if ((returned.primers)==0){ warning('primers not detected for ',name,call. = FALSE);return(NA)}
  if (returned.primers>0){
    designed.primers=data.frame()
    for (i in seq(0,returned.primers-1,1)){
      #IMPORT SEQUENCES
      id=sprintf(  'PRIMER_LEFT_%i_SEQUENCE',i)
      PRIMER_LEFT_SEQUENCE=as.character(out[out[,1]==id,][,2])
      id=sprintf(  'PRIMER_RIGHT_%i_SEQUENCE',i)
      PRIMER_RIGHT_SEQUENCE=as.character(out[out[,1]==id,][,2])
      
      #IMPORT PRIMING POSITIONS
      id=sprintf(  'PRIMER_LEFT_%i',i)
      PRIMER_LEFT=as.numeric(unlist(strsplit(as.vector((out[out[,1]==id,][,2])),',')))
      #PRIMER_LEFT_LEN=as.numeric(unlist(strsplit(as.vector((out[out[,1]==id,][,2])),',')))
      id=sprintf(  'PRIMER_RIGHT_%i',i)
      PRIMER_RIGHT=as.numeric(unlist(strsplit(as.vector((out[out[,1]==id,][,2])),',')))
      #IMPORT Tm
      id=sprintf(  'PRIMER_LEFT_%i_TM',i)
      PRIMER_LEFT_TM=as.numeric(as.vector((out[out[,1]==id,][,2])),',')
      id=sprintf(  'PRIMER_RIGHT_%i_TM',i)
      PRIMER_RIGHT_TM=as.numeric(as.vector((out[out[,1]==id,][,2])),',')
      
      res=out[grep(i,out[,1]),]
      extra.inf=t(res)[2,,drop=FALSE]
      colnames(extra.inf)=sub( paste("_",i,sep=""),"",res[,1])
      extra.inf=extra.inf[,-c(4:9),drop=FALSE] # remove redundant columns
      extra.inf=apply(extra.inf,2,as.numeric)
      #Aggegate in a dataframe
      primer.info=data.frame(i,
                             PRIMER_LEFT_SEQUENCE,PRIMER_RIGHT_SEQUENCE,
                             PRIMER_LEFT_TM, PRIMER_RIGHT_TM,
                             PRIMER_LEFT_pos=PRIMER_LEFT[1],
                             PRIMER_LEFT_len=PRIMER_LEFT[2], 
                             PRIMER_RIGHT_pos=PRIMER_RIGHT[1], 
                             PRIMER_RIGHT_len=PRIMER_RIGHT[2],
                             t(data.frame(extra.inf))
                             
      )
      rownames(primer.info)=NULL
      designed.primers=rbind(designed.primers, primer.info)
      #print(primer.info)
    }
    
    
    
    #colnames(designed.primers)=c('PrimerID',
    #                             'Fwseq','Rvseq',
    #                             'FwTm','RvTm',
    #                             'FwPos','Fwlen',
    #                             'RvPos','Rvlen',
    #                             'fragLen' )
    
  }
  return(designed.primers)
}


#' convert primer list to genomic intervals
#' 
#' function returns a GRanges or data frame object from a list of primers designed
#' by \code{designPrimers} function after calculating genomic location of the amplicon
#' targeted by the primers.
#' 
#' @param primers a list of primers returned by \code{designPrimers} function
#' @param as.data.frame logical indicating if a data frame should be returned
#'        instead of \code{GRanges} object.
#'        
#' @examples
#'  data(bisPrimers)
#'  # remove data with no primers found
#'  bisPrimers=bisPrimers[!is.na(bisPrimers)]
#'  gr.pr=primers2ranges(bisPrimers) # convert primers to GRanges
#'          
#' @seealso \code{\link{filterPrimers}}, \code{\link{designPrimers}}
#'        
#' @export
#' @docType methods
primers2ranges<-function(primers,as.data.frame=FALSE){
  
  if(any(is.na(primers))){
    warning( "There are targets without primers\nfiltering those before conversion")
    primers=primers[ !is.na(primers) ]
  }
  df=do.call("rbind",primers) # get primers to a df
  locs=gsub("\\|\\.+","",rownames(df)) # get the coordinates from list ids
  temp=do.call("rbind",strsplit(locs,"_")) #
  
  start=as.numeric(temp[,2])
  chr=as.character(temp[,1])
  
  
  
  amp.start= start + as.numeric(df$PRIMER_LEFT_pos)  
  amp.end  = start + as.numeric(df$PRIMER_RIGHT_pos)
  res=data.frame(chr=chr,start=amp.start,end=amp.end,df)
  #saveRDS(res,file="/work2/gschub/altuna/projects/DMR_alignments/all.designed.primers.to.amps.rds")
  if(as.data.frame)
  {
    return(res)
  }
  gr=GRanges(seqnames=res[,1],ranges=IRanges(res[,2],res[,3]) )
  values(gr)=res[,-c(1,2,3)]
  gr
}

Hi,
Thanks for sharing the code. This could be very useful.

I tried to get the code as indicated in the second post but I get this error message:
Error: could not find function "set_config"

I am new to GitHub, perhaps there are additional packages I need to install or set up a proxy separately.

Did anyone experience anything similar?

Best,
Massimo