Calculating Dual Wield Character DPS

I've been hacking through several formulas across this site and others. I'm running into problems trying to figure out the true DPS when the character is dual wielding. Let's take a low level Barbarian for example.

Strength: 28
Damage Increased by Skills: 0%
Attacks per second: 1.24
Crit Chance: 5%
Crit Hit Damage: 50%

Weapon Stats:
1 Hand Spear: 7-11 Damage
Spear Base Attacks per Second: 1.20
Bonus: Increase Attack Speed by 3%

So, the formula for this would be (or any one handed character):

7 + 11 = **18**; (weapon damage range added together)
1.20 * (1 + (3 * 0.01)) = **1.236**; (base weapon speed, times any IAS bonus on the weapon plus 1)
(0 * 0.01) + 1 = **1**; (damage bonus from skills. this character has 0)
((5 * 0.01) * (50 * 0.01)) + 1 = **1.025**; (crit chance * crit damage)
(28 * 0.01) + 1 = **1.28**; (attribute to percent + 1)

multiple all of the results above, and divide by two and you get: 14.59

which is the correct DPS of the character. But now, how would you calculate the DPS of an offhand weapon equipped to this character, say:

1H Axe
Base Speed: 1.30
Damage Range: 9-14

Does anyone know how to calculate this?

The actual formula the game calculates damage is:

(AvgMainHandHit + AvgOffHandHit) / (MainHandSwingTime + OffHandSwingTime)

which equals:

( Average Double Hit Damage ) / ( Average Double Hit Time ).

I purposefully named it Hands, because we calculate both weapon and character statistics into it.

The formula for damage is:

(1 + passive skill boosts)(Average Weapon Damage + ((minimum damage bonus + maximum damage bonus)/2))(Weapon Damage Multipliers)(Attack Speed)(1 + ( crit% * crit damage %))*( 1 + (main stat / 100))

For Dual Wielding:

((1 + passive skill boosts)(Weapon 1 average damage + ((minimum damage bonus + maximum damage bonus)/2))(Weapon Damage Multipliers)(Attack Spee)(1 + ( crit% * crit damage %))( 1 + (main stat / 100))(average attack speed of both weapons / weapon 1 attack speed) + (1 + passive skill boosts)(Weapon 2 average damage + ((minimum damage bonus + maximum damage bonus)/2))(Weapon Damage Multipliers)(Attack Speed)(1 + ( crit% * crit damage %))( 1 + (main stat / 100))(average attack speed of both weapons / weapon 2 attack speed)) * 0.575