# distrib

How to download and try this example

    Usage: pl -gif distrib.htm
    or for postscript output: pl -ps distrib.htm | lp

    This is a more elaborate example that involves variables, a loop,
    automatically calculated distributions for the histograms, etc.

    //  set landscape mode and do page title using proc page
    #proc page
    landscape: yes
    pagesize: 11 8.5
    #if @DEVICE in gif,png
      scale: 0.5
    #endif
    title:  Distribution of Scores Over Time
    	Protocol 7 vs. Protocol B
    	06-30-99

    //  read file vf.dat using proc getdata
    #proc getdata
    file: vf.dat

    //  set some variables..

    // I will be our loop counter..
    #set I = 1

    // make a list of the data fields to use for each left member of pair ..
    // (rt member will be +1)
    #set FIELDLIST = 7,9,11,13

    // make a list of X left locations for each pair in inches..
    #set XPOSLIST = 1,3.5,6,8.5

    // make a list of labels for each pair
    #set LABELLIST = "Baseline,1_yr_visit,2_yr,3_yr"

    //  loop, once for each pair..
    #loop

      // get parameters from lists..
      #set FLD = $nmember(@I,@FIELDLIST)
      #if $strlen(@FLD) < 1
        #break
      #endif
      #set XPOS = $nmember(@I,@XPOSLIST)
      #set LABEL = $nmember(@I,@LABELLIST)
      #set LABEL = $change( "_", " ", @LABEL )

      //////////////////////////
      // first do left of pair..
      //////////////////////////

      //  set up plotting area for histogram (left member of pair) using proc areadef
      #proc areadef
      box: 1 2.5
      location: @XPOS 4
      xrange: 0 40
      yrange: 0 100
      #saveas A

      //  if the leftmost pair, do a Y axis using proc yaxis
      #if @I = 1
        #proc yaxis
        stubs: inc 10
        label: Score
        labeldistance: 0.7
        stubslide: -2.5(s)
        ticlen: 0 0
      #endif

      //  if the rightmost pair, do a Y axis using proc yaxis
      #if @I = 4
        #proc yaxis
        location: 10.2
        label: Score
        labeldistance: -0.7
        stubs: inc 10
        stubdetails: adjust=0.5,0
        stubslide: -2.5(s)
        ticlen: 0 0
      #endif

      //  render label above pair using proc annotate
      #proc annotate
      location: max-0.2 max+0.2
      textdetails: align=C
      text: @LABEL

      //  compute distribution for histogram using proc tabulate
      #proc tabulate
      axis1: y
      datafield1: @FLD
      rangespec1: 0 5 95
      percents: yes
      select: @@4 = B
      showrangelowonly: yes
      #saveas: T

      //  we cannot do a histogram if N is too low.. find N using proc processdata
      // (the variable TOTALS will be set)..
      #proc processdata
      action: total
      fields: 2
      #endproc

      // only do the histogram if we have > 10 cases..
      #if @TOTALS > 10

        //  render histogram using proc bars
        #proc bars
        horizontalbars: yes
        locfield:  1
        lenfield:  3
        barwidth: 0.08
        #saveas B

      #endif

      //  now set up plotting area for rangebars using proc areadef
      #proc areadef
      box: 1 2
      location: @XPOS 1
      xrange: 0 1
      yrange: 0 100
      #saveas A2

      //  if leftmost pair do a Y axis using proc yaxis
      #if @I = 1
        #proc yaxis
        stubs: inc 10
        label: Score
        labeldistance: 0.7
      #endif
      //  if rightmost pair do a Y axis using proc yaxis
      #if @I = 4
        #proc yaxis
        location: 10.2
        label: Score
        labeldistance: -0.7
        stubs: inc 10
        stubdetails: adjust=0.5,0
        ticlen: -0.1
      #endif

      //  get back to original set of data (proc originaldata)
      #proc originaldata

      //  render rangebar using proc rangebar
      #proc rangebar
      select: @@4 = B
      datafield: @FLD
      barloc: 0.25
      mediansym: shape=circle style=filled fillcolor=0.3
      nlocation: -10(s)
      color: 0.9
      #saveas R

      ////////////////////////////
      // now do right of pair..
      // (repeat of procedure above)
      ////////////////////////////

      #set XPOS = $arith(@XPOS+1.0)

      // do histogram..
      #proc areadef
      #clone A
      location: @XPOS 4

      #proc tabulate
      #clone: T
      select: @@4 = 7

      // see if total is high enough to display histogram..
      #proc processdata
      action: total
      fields: 2
      #endproc

      // only do the histogram if we have > 10 cases..
      #if @TOTALS > 10

        #proc bars
        #clone B

      #endif

      // do rangebar..
      #proc areadef
      #clone: A2
      location: @XPOS 1

      // get back to data set originally read..
      #proc originaldata

      #proc rangebar
      #clone R
      select: @@4 = 7
      barloc: 0.15
      datafield: @FLD

      #set I = $arith(@I+1)

    #endloop