Psychrometric Chart Problem

Hello Everyone!

First-- thank you for all the hard work. The fact that Ladybug exists is amazing.

Second-- my problem. I am trying to break up psychrometric analysis by season and by day/night, so 8 graphs total (4 seasons, 2 conditions). I am just going to do this with four separate psychrometric chart components. I can use the analysis period to block out the 4 seasons, no problem. I can also write a conditional statement using c<=0 for direct radiation to get whether it is nighttime or daytime (or something in between if I use a value other than zero). However, when I try to connect both, I receive an error:

“1. Solution exception:global name ‘getHOYsBasedOnPeriod’ is not defined”

I’ve updated my ladybug, and replaced all the components involved. I attach the file that I’m working on, and the Vienna weather data that I’m using as a test.

Thoughts or help would be much appreciated! (Under a bit of a deadline here, actually)

Alexander (676 KB)
AUT_Vienna.Schwechat.110360_IWEC.epw (1.48 MB)


There was a bug that only affected cases where you have both an analysisPeriod and a conditional statement connected. I have fixed it in the version on the github and in the attached GH file.

Also, the operation you describe can be done with just one psychrometric chart component like so:

(see attached GH file for how it works).


-Chris (406 KB)