plotstat.tcl

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/*  plotstat.tcl --*/
/* */
/*     Set of very simple drawing routines, belonging to the statistics*/
/*     package*/
/* */
/*  version 0.1: initial implementation, january 2003*/

namespace ::math::statistics {}

/*  plot-scale*/
/*     Set the scale for a plot in the given canvas*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     xmin     Minimum x value*/
/*     xmax     Maximum x value*/
/*     ymin     Minimum y value*/
/*     ymax     Maximum y value*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Array elements set*/
/* */
ret  ::math::statistics::plot-scale ( type canvas , type xmin , type xmax , type ymin , type ymax ) {
    variable plot

    if { $xmin == $xmax } { set xmax [expr {1.1*$xmin+1.0}] }
    if { $ymin == $ymax } { set ymax [expr {1.1*$ymin+1.0}] }

    set plot($canvas,xmin) $xmin
    set plot($canvas,xmax) $xmax
    set plot($canvas,ymin) $ymin
    set plot($canvas,ymax) $ymax

    set cwidth  [$canvas cget -width]
    set cheight [$canvas cget -height]
    set cx      20
    set cy      20
    set cx2     [expr {$cwidth-$cx}]
    set cy2     [expr {$cheight-$cy}]

    set plot($canvas,cx)   $cx
    set plot($canvas,cy)   $cy

    set plot($canvas,dx)   [expr {($cwidth-2*$cx)/double($xmax-$xmin)}]
    set plot($canvas,dy)   [expr {($cheight-2*$cy)/double($ymax-$ymin)}]
    set plot($canvas,cx2)  $cx2
    set plot($canvas,cy2)  $cy2

    $canvas create line $cx $cy $cx $cy2 $cx2 $cy2 -tag axes
}

/*  plot-xydata*/
/*     Create a simple XY plot in the given canvas (collection of dots)*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     xdata    Series of independent data*/
/*     ydata    Series of dependent data*/
/*     tag      Tag to give to the plotted data (defaults to xyplot)*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple xy graph in the canvas*/
/* */
/*  Note:*/
/*     The tag can be used to manipulate the xy graph*/
/* */
ret  ::math::statistics::plot-xydata ( type canvas , type xdata , type ydata , optional tag =xyplot ) {
    PlotXY $canvas points $tag $xdata $ydata
}

/*  plot-xyline*/
/*     Create a simple XY plot in the given canvas (continuous line)*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     xdata    Series of independent data*/
/*     ydata    Series of dependent data*/
/*     tag      Tag to give to the plotted data (defaults to xyplot)*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple xy graph in the canvas*/
/* */
/*  Note:*/
/*     The tag can be used to manipulate the xy graph*/
/* */
ret  ::math::statistics::plot-xyline ( type canvas , type xdata , type ydata , optional tag =xyplot ) {
    PlotXY $canvas line $tag $xdata $ydata
}

/*  plot-tdata*/
/*     Create a simple XY plot in the given canvas (the index in the list*/
/*     is the horizontal coordinate; points)*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     tdata    Series of dependent data*/
/*     tag      Tag to give to the plotted data (defaults to xyplot)*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple xy graph in the canvas*/
/* */
/*  Note:*/
/*     The tag can be used to manipulate the xy graph*/
/* */
ret  ::math::statistics::plot-tdata ( type canvas , type tdata , optional tag =xyplot ) {
    PlotXY $canvas points $tag {} $tdata
}

/*  plot-tline*/
/*     Create a simple XY plot in the given canvas (the index in the list*/
/*     is the horizontal coordinate; line)*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     tdata    Series of dependent data*/
/*     tag      Tag to give to the plotted data (defaults to xyplot)*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple xy graph in the canvas*/
/* */
/*  Note:*/
/*     The tag can be used to manipulate the xy graph*/
/* */
ret  ::math::statistics::plot-tline ( type canvas , type tdata , optional tag =xyplot ) {
    PlotXY $canvas line $tag {} $tdata
}

/*  PlotXY*/
/*     Create a simple XY plot (points or lines) in the given canvas*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     type     Type: points or line*/
/*     tag      Tag to give to the plotted data*/
/*     xdata    Series of independent data (if empty: index used instead)*/
/*     ydata    Series of dependent data*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple xy graph in the canvas*/
/* */
/*  Note:*/
/*     This is the actual routine*/
/* */
ret  ::math::statistics::PlotXY ( type canvas , type type , type tag , type xdata , type ydata ) {
    variable plot

    if { ![info exists plot($canvas,xmin)] } {
    return -code error -errorcode "No scaling given for canvas $canvas"
    }

    set xmin $plot($canvas,xmin)
    set xmax $plot($canvas,xmax)
    set ymin $plot($canvas,ymin)
    set ymax $plot($canvas,ymax)
    set dx   $plot($canvas,dx)
    set dy   $plot($canvas,dy)
    set cx   $plot($canvas,cx)
    set cy   $plot($canvas,cy)
    set cx2  $plot($canvas,cx2)
    set cy2  $plot($canvas,cy2)

    set plotpoints [expr {$type == "points"}]
    set xpresent   [expr {[llength $xdata] > 0}]
    set idx        0
    set coords     {}

    foreach y $ydata {
    if { $xpresent } {
        set x [lindex $xdata $idx]
    } else {
        set x $idx
    }
    incr idx

    if { $x == {}    } continue
    if { $y == {}    } continue
    if { $x >  $xmax } continue
    if { $x <  $xmin } continue
    if { $y >  $ymax } continue
    if { $y <  $ymin } continue

    if { $plotpoints } {
        set xc [expr {$cx+$dx*($x-$xmin)-2}]
        set yc [expr {$cy2-$dy*($y-$ymin)-2}]
        set xc2 [expr {$xc+4}]
        set yc2 [expr {$yc+4}]
        $canvas create oval $xc $yc $xc2 $yc2 -tag $tag -fill black
    } else {
        set xc [expr {$cx+$dx*($x-$xmin)}]
        set yc [expr {$cy2-$dy*($y-$ymin)}]
        lappend coords $xc $yc
    }
    }

    if { ! $plotpoints } {
    $canvas create line $coords -tag $tag
    }
}

/*  plot-histogram*/
/*     Create a simple histogram in the given canvas*/
/* */
/*  Arguments:*/
/*     canvas   Canvas widget to use*/
/*     counts   Series of bucket counts*/
/*     limits   Series of upper limits for the buckets*/
/*     tag      Tag to give to the plotted data (defaults to xyplot)*/
/* */
/*  Result:*/
/*     None*/
/* */
/*  Side effect:*/
/*     Simple histogram in the canvas*/
/* */
/*  Note:*/
/*     The number of limits determines how many bars are drawn,*/
/*     the number of counts that is expected is one larger. The*/
/*     lower and upper limits of the first and last bucket are*/
/*     taken to be equal to the scale's extremes*/
/* */
ret  ::math::statistics::plot-histogram ( type canvas , type counts , type limits , optional tag =xyplot ) {
    variable plot

    if { ![info exists plot($canvas,xmin)] } {
    return -code error -errorcode DATA "No scaling given for canvas $canvas"
    }

    if { ([llength $counts]-[llength $limits]) != 1 } {
    return -code error -errorcode ARG \
        "Number of counts does not correspond to number of limits"
    }

    set xmin $plot($canvas,xmin)
    set xmax $plot($canvas,xmax)
    set ymin $plot($canvas,ymin)
    set ymax $plot($canvas,ymax)
    set dx   $plot($canvas,dx)
    set dy   $plot($canvas,dy)
    set cx   $plot($canvas,cx)
    set cy   $plot($canvas,cy)
    set cx2  $plot($canvas,cx2)
    set cy2  $plot($canvas,cy2)

    #
    # Construct a sufficiently long list of x-coordinates
    #
    set xdata [concat $xmin $limits $xmax]

    set idx   0
    foreach x $xdata y $counts {
    incr idx

    if { $y == {}    } continue

    set x1 $x
    if { $x <  $xmin } { set x1 $xmin }
    if { $x >  $xmax } { set x1 $xmax }

    if { $y >  $ymax } { set y $ymax }
    if { $y <  $ymin } { set y $ymin }

    set x2  [lindex $xdata $idx]
    if { $x2 <  $xmin } { set x2 $xmin }
    if { $x2 >  $xmax } { set x2 $xmax }

    set xc  [expr {$cx+$dx*($x1-$xmin)}]
    set xc2 [expr {$cx+$dx*($x2-$xmin)}]
    set yc  [expr {$cy2-$dy*($y-$ymin)}]
    set yc2 $cy2

    $canvas create rectangle $xc $yc $xc2 $yc2 -tag $tag -fill blue
    }
}

/* */
/*  Simple test code*/
/* */
if { [info exists ::argv0] && ([file tail [info script]] == [file tail $::argv0]) } {

     xdata =  {1 2 3 4 5 10 20 6 7 8 1 3 4 5 6 7}
     ydata =  {2 3 4 5 6 10 20 7 8 1 3 4 5 6 7 1}

    canvas .c
    canvas .c2
    pack   .c .c2 -side top -fill both
    ::math::statistics::plot-scale .c  0 10 0 10
    ::math::statistics::plot-scale .c2 0 20 0 10

    ::math::statistics::plot-xydata .c  $xdata $ydata
    ::math::statistics::plot-xyline .c  $xdata $ydata
    ::math::statistics::plot-histogram .c2 {1 3 2 0.1 4 2} {-1 3 10 11 23}
    ::math::statistics::plot-tdata  .c2 $xdata
    ::math::statistics::plot-tline  .c2 $xdata
}