# set terminal canvas  rounded size 600,400 enhanced fsize 10 lw 1.6 fontscale 1 name "rgbalpha_2" jsdir "."
# set output 'rgbalpha.2.js'
set key title "Plot style rgbalpha" center
set key at screen 0.75, 0.75 left bottom vertical Left noreverse enhanced autotitle nobox
set key noinvert samplen 1 spacing 1 width -7 height 0 
set object  1 rect from screen 0, 0 to screen 1, 1
set object  1 behind clip lw 1.0  dashtype solid fc  rgb "grey10"  fillstyle   solid 1.00 noborder
set samples 128, 128
set size ratio 0.95 1,1
set style data lines
set xrange [ 0.00000 : 128.000 ] noreverse nowriteback
set yrange [ 0.00000 : 128.000 ] noreverse nowriteback
set lmargin at screen 0.1
set bmargin at screen 0.1
set tmargin at screen 0.9
focus(x,y) = ((column(0)-x)**2 + (column(-1)-(127-y))**2) > 400 ? 0 : 255
x = 0.0
GPFUN_focus = "focus(x,y) = ((column(0)-x)**2 + (column(-1)-(127-y))**2) > 400 ? 0 : 255"
## Last datafile plotted: "lena.rgb"
plot 100.*(.4+sin(x/5.)/(x/5.)) lw 5 title 'solid line',      'lena.rgb' binary array=(128,128) format="%uchar" flipy using 1:2:3:(focus(70,50))                 with rgbalpha title "Lena with circular mask"