Electric flux

_.md

[ Launch: Electric flux ] 5789177 by bvancil
[ Launch: Electric flux ] 5784501 by bvancil
[ Launch: Bee in Browser ] 5784493 by bvancil
[ Launch: Glowscript? ] 5593124 by elsherbini

config.json

{"description":"Electric flux","endpoint":"","display":"div","public":true,"require":[{"name":"glowscript","url":"https://bitbucket.org/davidscherer/glowscript/raw/8af3ac25a24e733367472159f7f2e1a0ca276dbc/package/glow.1.0.min.js"},{"name":"compiler","url":"https://bitbucket.org/davidscherer/glowscript/raw/8af3ac25a24e733367472159f7f2e1a0ca276dbc/package/compiler.1.0.min.js"},{"name":"symbols","url":"https://bitbucket.org/davidscherer/glowscript/raw/8af3ac25a24e733367472159f7f2e1a0ca276dbc/package/symbols.1.0.min.js"}],"fileconfigs":{"inlet.js":{"default":true,"vim":false,"emacs":false,"fontSize":12},"config.json":{"default":true,"vim":false,"emacs":false,"fontSize":12},"_.md":{"default":true,"vim":false,"emacs":false,"fontSize":12}},"fullscreen":false,"play":false,"loop":false,"restart":false,"autoinit":true,"pause":true,"loop_type":"period","bv":false,"nclones":15,"clone_opacity":0.4,"duration":3000,"ease":"linear","dt":0.01}

inlet.js

var body = d3.select("#display");
body.append("div")
	.attr("id", "glowscript")
	.attr("class", "glowscript")
	.append("p")
	.text("In GlowScript programs: Rotate the camera by dragging with the right mouse button. To zoom, drag with the left+right mouse buttons, or use the mouse wheel.")
	.style("max-width", "726px");



//You can change all the parameters in this section to see how it affects the output
window.__context = { glowscript_container:    $("#glowscript").removeAttr("id") }
var scene = canvas()


scene.forward = vec(-13,2.2684953747456,1.936)
scene.fov= 0.400919887872002

// Originally from http://tributary.io/inlet/5593124
// Pasted from http://www.glowscript.org/#/user/Frank_Noschese/folder/My_Programs/program/Electric_flux_through_a_square/edit
// Converted from the VPython program BrilliantGaussLaw

//Constants
var q = 1e-9 //charge
var k = 9e9 //electrostatic constant
var L = 1.0 //length of square face
var dL = 0.2*L //size of dA <-- CHANGE THIS TO MAKE FLUX MORE/LESS ACCURATE

//Objects
sphere ( {pos:vec(0,0,0), color:color.red, size: vec(1,1,1).multiply(2*0.05*L)} )

//intitial conditions
var obs = vec(L,dL/2,dL/2)
var dFlux = 0
var Flux = 0

while (obs.z < L) { 
    obs.y = 0
    while (obs.y < L) { 
        box( {pos:obs, size:vec(0.01*L, dL, dL), color:color.green} )
        var E = norm(obs).multiply(k*q/mag2(obs))
        arrow( {pos:obs, axis_and_length:E.multiply(0.1), color:color.orange, shaftwidth:dL/5} )
        dFlux = E.x*dL*dL
        Flux = Flux + dFlux
        obs.y = obs.y + dL
    }
    obs.z = obs.z + dL

}
print("Flux=",Flux,"Vm") // scroll down for this
//$('body').append('<p>Flux='+Flux+'Vm</p')