set usage {
    usage: crosstab.tcl infile ?-c x,y? ?-sep '\t'? -w 12
    Reads the infile (or stdin if infile is "-") for cases
    Prints on stdout a cross-tabulation for the specified columns.
    -c x,y : columns to use (1...), default is 1,2
    -sep x : column separator, default is ";"
    -w   n : output column width, default is 12
 }
 if {[llength $argv] == 0} {puts stderr $usage; exit 1}

 proc main argv {
     getopt argv -sep sep  ";" 
     set sep [subst $sep] ;#-- e.g. for \t
     getopt argv -c   cols 1,2
     getopt argv -w   w    12
     
     set infile [lindex $argv 0]
     if {$infile eq "-"} {
         set f stdin
     } elseif {[file exists $infile]} {
         set f [open $infile]
     } else {puts stderr "no such file $infile\n$::usage"; exit 1}
     
     foreach {x y z} [split $cols ,] break
     incr x -1; incr y -1
     if {$z ne ""} {incr z -1}
     while {[gets $f line] >= 0} {
         set fields [split $line $sep]
         set key [lindex $fields $x],[lindex $fields $y],
         if {$z ne ""} {append key [lindex $fields $z]}
         inc N($key)
     }
     if {$f ne "stdout"} {close $f}
     
     set xs [get_values N 0]
     set ys [get_values N 1]
     if {$z ne ""} {
         set zs [get_values N 2]
     } else {set zs {{}}}
     set totals [lrepeat [llength $ys] [lrepeat [llength $xs] 0]]
     set ylabels [map [list format %-${w}s] [concat $ys Total]]
     foreach zv $zs {
         array unset a
         foreach i [array names N *,$zv] {
             foreach {p1 p2} [split $i ,] break
             set a($p1,$p2) $N($i)
         }
         set m [marray a $xs $ys]
         set totals [mexpr $totals + $m]
         set m [mlabel [msums $m] [concat $xs Total] $ylabels]
         puts $zv\n[mformat $m $w 1]\n
     }
     if {$zs ne "{}"} {
         set m [mlabel [msums $totals] [concat $xs Total] $ylabels]
         puts "Grand Total:\n[mformat $m $w 1]\n"
     }
 }
#------------------------ additional list functions
 proc lrepeat {n args} { #-- built-in from 8.5
    set res {}
    for {set i 0} {$i<$n} {incr i} {eval lappend res $args}
    set res
 }
#-- [Map] a function to a list, returning the results
 proc map {script list} {
    set res {}
    foreach i $list {lappend res [eval [linsert $script end $i]]}
    set res
 }
#-- Sum of a list
 proc lsum list {
    set res 0
    foreach i $list {set res [expr {$res+$i}]}
    set res
 }
#-- Apply a binary operator element-wise to two matrixes, giving a third
 proc mexpr {mat1 op mat2} {
    set res {}
    foreach row1 $mat1 row2 $mat2 row "" {
        foreach col1 $row1 col2 $row2 {
            lappend row [expr {$col1} $op {$col2}]
        }
        lappend res $row
    }
    set res
 }
#-- Create a matrix from an array with (x,y) keys
 proc marray {_arr cols rows} {
    upvar 1 $_arr arr
    set res {}
    foreach row $rows {
        set outrow {}
        foreach col $cols {lappend outrow [get arr($col,$row)]}
        lappend res $outrow
    }
    set res
 }

#-- Compute row and columns sums, and add them to a matrix (at right resp. bottom
 proc msums matrix {
    set ncol -1
    set ncols {}
    foreach i [lindex $matrix 0] {
        set [incr ncol] 0
        lappend ncols $ncol
    }
    set res {}
    foreach row $matrix {
        foreach cell $row ncol $ncols {
            set $ncol  [expr {[set $ncol]+$cell}]
        }
        lappend res [lappend row [lsum $row]]
    }
    set colsums {}
    foreach i [lindex $matrix 0] ncol $ncols {
        lappend colsums [set $ncol]
    }
    lappend res [lappend colsums [lsum $colsums]]
 }

#-- turn a matrix into a formatted multiline string
 proc mformat {matrix {w 12} {underline 0}} {
    set res ""
    foreach row $matrix line "" {
        foreach cell $row {append line [format %${w}s $cell]}
        lappend res $line
    }
    if $underline {
        set length [string length [lindex $res 0]]
        set res [linsert $res 1 [string repeat - $length]]
    }
    join $res \n
 }

#-- Add column and row labels to a matrix
 proc mlabel {matrix collabels {rowlabels {}}} {
    #-- Add column and row labels to a matrix
    set res [list [linsert $collabels 0 {}]]
    foreach row $matrix label $rowlabels {
        lappend res [linsert $row 0 $label]
    }
    set res
 }
#-- Retrieve a variable's value, if present, else 0
 proc get _var {
     upvar 1 $_var var
     if {[info exists var]} {set var} else {return 0}
 }
#-- Get the values of (x,y,...) array keys by position
 proc get_values {_arr pos} {
     upvar 1 $_arr arr
     set values {}
     foreach i [array names arr] {
         lappend values [lindex [split $i ,] $pos]
     }
     lsort -unique $values
 }
#-- See [getopt] for discussion
 proc getopt {_argv name {_var ""} {default ""}} {
     upvar 1 $_argv argv $_var var
     set pos [lsearch -regexp $argv ^$name]
     if {$pos>=0} {
         set to $pos
         if {$_var ne ""} {
             set var [lindex $argv [incr to]]
         }
         set argv [lreplace $argv $pos $to]
         return 1
     } else {
         if {[llength [info level 0]] == 5} {set var $default}
         return 0
     }
 }
#-- auto-initializing increment (standard in 8.5)
 proc inc {_var {amount 1}} {
     upvar 1 $_var var
     if ![info exists var] {set var 0}
     incr var $amount
 }

 main $argv