Interesting point. I simply relied o this post of Mike Bostock http://bost.ocks.org/mike/chart/.
textures.circles()
.radius(4)
.fill("transparent")
.strokeWidth(2);
could initially be var circles = textures.circles({
radius: 4,
fill: "transparent",
strokeWidth: 2
});
and later updated to be circles.strokeWidth( 1 );
Which works rather nicely especially when the config object is generated dynamically.