calc_volume.rb

# calculates E volumetric value given widthxheightxlength
# Usage: width height length

if ARGV.size < 3
    puts "Usage: width height length"
    exit 1
end

$layer_width = ARGV[0].to_f
$layer_height = ARGV[1].to_f
$dist = ARGV[2].to_f

def calc_e(dist)
    diameter = $layer_height
    circle_area = (diameter ** 2) * Math::PI / 4.0
    rectangular_width = $layer_width - diameter
    extrusion_crosssection_area = (rectangular_width * $layer_height) + circle_area
    volume = extrusion_crosssection_area * dist
    volume
end

puts "for length #{$dist} E: #{calc_e($dist)}"
# if 3rd param is radius
c = 2.0 * Math::PI * $dist
puts "for radius #{$dist} circumferance #{c} E: #{calc_e(c)}"