问如何更改Tcl默认字体大小

EN

font create myDefaultFont -family Helvetica -size 20
option add *font myDefaultFont

proc DisplayModel2D { {ShapeType nill} {dAmp 5}  {xLoc 10} {yLoc 10} {xPixels 512} {yPixels 384} {nEigen 1} } {
    global TunitTXT
    global ScreenResolutionX ScreenResolutionY
    if {  [info exists TunitTXT] != 1} {set TunitTXT ""}
    if {  [info exists ScreenResolutionX] != 1} {set ScreenResolutionX 1024}
    if {  [info exists ScreenResolutionY] != 1} {set ScreenResolutionY 768}

    if {$xPixels == 0} {
        set xPixels [expr int($ScreenResolutionX/2)];       
        set yPixels [expr int($ScreenResolutionY/2)];
        set xLoc 10
        set yLoc 10
    }
    if {$ShapeType == "nill"} {
        puts ""; puts ""; puts "------------------"
        puts "View the Model? (N)odes, (D)eformedShape, anyMode(1),(2),(#). Press enter for NO."
        gets stdin answer
        if {[llength $answer]>0 } { 
            if {$answer != "N" & $answer != "n"} {
                puts "Modify View Scaling Factor=$dAmp? Type factor, or press enter for NO."
                gets stdin answerdAmp
                if {[llength $answerdAmp]>0 } { 
                    set dAmp $answerdAmp
                }
            }
            if {[string index $answer 0] == "N" || [string index $answer 0] == "n"} {
                set ShapeType NodeNumbers
            } elseif {[string index $answer 0] == "D" ||[string index $answer 0] == "d" } {
                set ShapeType DeformedShape
            } else {
                set ShapeType ModeShape
                set nEigen $answer
            }
        } else {
            return
        }
    }

    if {$ShapeType ==  "ModeShape" } {
        set lambdaN [eigen $nEigen];        # perform eigenvalue analysis for ModeShape
        set lambda [lindex $lambdaN [expr $nEigen-1]];
        set omega [expr pow($lambda,0.5)]
        set PI  [expr 2*asin(1.0)];     # define constant
        set Tperiod [expr 2*$PI/$omega];        # period (sec.) 
        set fmt1 "Mode Shape, Mode=%.1i Period=%.3f %s  "
        set windowTitle [format $fmt1 $nEigen $Tperiod  $TunitTXT]
    } elseif  {$ShapeType ==  "NodeNumbers" } {
        set windowTitle "Node Numbers"  
    } elseif  {$ShapeType ==  "DeformedShape" } {
        set windowTitle "Deformed Shape"
    }

    set viewPlane XY
    recorder display $windowTitle $xLoc $yLoc $xPixels $yPixels  -wipe ; # display recorder
    DisplayPlane $ShapeType $dAmp $viewPlane $nEigen 0
}