Wallacei used to optmize EUI and sDA - generation doesn't run

Dear All,

I am using the Wallacei for the first time to run my multi-criteria optimization. I am using Rhino/Grasshopper via Rhino inside Revit plugin.
I set up energy simulation and daylight simulation using Honeybee and Ladybug.
My objective is to minimize the Energy Use Intensity (EUI) and maximize spatial Daylight Autonomy (sDA). My genomes are sliders that change building dimensions (in total 5 sliders).
I set up the component Wallacei correctly (I hope).

When I run the generation of solutions, it only reads the value of sDA and EUI that were previously calculated when I ran the simulations for the first time. It seems that the sliders are not changed and any simulation in Honeybee is triggered and any generation is provided. I tried with popoluation size of 50 and 5000. With the population of 5000 it gets stucked.

Could you help me to define if it is a problem with Wallacei settings, a problem with the simulations or other issues?

Many thanks!


Hi Julia,

please upload your definition so i can have a look… the reason you are not seeing charts is likely because when the sliders change, they dont impact the fitness values…

1 Like

Hi Mohammed,

I finally figured out why the optimization doesn’t work. When I run the Wallacei it changes the number separator from “.” to “,” in Honeybee nodes.

Wallacei moves sliders of genes, so my geometry changes but, the Honeybee cannot calculate the simulation because of this change from “.” to “,” . The value of the objective is null.

I have no idea why Wallace makes these changes with the separator and no idea how to fix it.

I am using Rhino 7 and LTB plugin 1.6 of Ladybug tools.

I would appreciate any suggestion on how to approach this problem.

Many thanks!

Best regards,


make sure you connect the numbers directly from the outputs of one component to the input of other components without going through a panel component. let me know if it solves the issue.

Dear Milad,
I have the same problem as Julia. After using the Wallacei, decimal separator changes. Simple presentation below with presented of the division result:

Unfortunatelly I cannot remove Panels completely, because GH generates text input file to external program, which works as Panel.

Did you find any solution or do you have any other ideas?

Inspired by post of Michael Visual: Grasshopper decimal separator
I set decimal separator after each change of the genes pool.


from ghpythonlib.componentbase import executingcomponent as component
import Grasshopper, GhPython
import System
import Rhino
import rhinoscriptsyntax as rs

class MyComponent(component):
	def RunScript(self, x=[]):
		#update separator to dot
		new_culture = System.Globalization.CultureInfo(System.Globalization.CultureInfo.CurrentCulture.Name)
		new_decimal_separator = "."
		new_culture.NumberFormat.NumberDecimalSeparator = new_decimal_separator
		System.Globalization.CultureInfo.CurrentCulture = new_culture
		#check separator
		separator = System.Globalization.CultureInfo.CurrentCulture.NumberFormat.NumberDecimalSeparator
		timestamp = System.DateTime.Now
		return x

In my project I have two gens pools, but its enough to insert script after one of them.