Ladybug's Solar radiation won't read the EPW file

Hello everyone,
I was trying to run the solar radiation analysis using Mostafa’s Ladybug plugin, but i am stuck at the very first step. The 'Generate Sky Matric’node won’t read the EPW file. Have tried with so many different EPW files with no luck.

Can anyone please help me out with this problem?

Hi, I’ve experienced some of the same issues: although it seems you have another error. Have you tried specifying your own working directory?

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Solved that problem by relocating everything in lication without white spaces, but now the Solar Radiation Analysis node giving an error "Vector object has no attribute "AngleBetween’"
Any idea how to solve this?

Hi @ABHIJEET_SHARMA1 and @jostein_olsen.

The last issue should be a change in DynamoAPI. I’m updating the nodes right now and will update this discussion as soon as I have a new version of the package uploaded. I’m also adding a better error logging so at least we will know what goes wrong with the batch run.

For the next major release all the analysis components will be replaced by fully radiance-based methods so we won’t have issues such as this one.

I pushed a new version (0.1.1) which should handle all the cases that you mentioned about file path.

Also AngleBetween has changed to AngleWithVector. This is also fixed. Radiation analysis should run with no issues.

Let me know if you still have issues.


Thanks Mostapha for the update, will try and post again.

Tried this now and it seems to be working! Yeah! :slight_smile: Although this is not a solar analysis forum I still want to question one of my test results, because it seems that the Northward facing facade recieves the most solar radiation and not the southward facing facade. Any idea of why this is? I have no rotation from true north in my model. (The .epw file is from Oslo, Norway btw…)

Nice to see that it’s finally running. The results doesn’t look right! Let me check a couple of options and report back. I’m in the middle of replacing the current method with what I mentioned above.

Ok, thanks! I’ve done some comparisons to the solar analysis addin you can download for Revit as well. It’s also based on Radiance as far as I could tell? And the results was very varied. Unfortunately I don’t have the images at the moment.

No worries! let me update it all and then we can run more tests. It will take couple of days. As far as I know Revit uses Ecotect engine for solar radiation calculation which is not using radiance.

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@jostein_olsen It’s fixed! Download Ladybug 0.1.2. It is still the old method (which will be replaced soon). I checked the values against radiance. Thanks for reporting the issue.

Hi Mostapha

I just download your latest version for Ladybug in dynamo 1.3, and for the sunlight hours analysis in the color surface the input Analysis surface didnt appear, so i download a preview version where everything seems ok, but the epw file didnt work. So I copy the node from the preview version to the latest. but i still get an error a the values are “Null”, Any advice???

Hi @samuel_barcenas,

Did you try to use Honeybee sunlighthours node instead? I wrote a new
sunlighthours component for Honeybee which uses Radiance and should be more
stable and faster than the ladybug node.


Hello Mostapha,
First of all thank you for all the great stuff you are creating here and for grasshopper.

I installed the ladybug package but unfortunately I can’t get the radiationAnalysis.dyn to work properly. Up in the example the last node read “Color Surface” and it takes three inputs. However when I open the example, the last node has two parameters only ( _analysisSurfaces ) is missing. I opened the and there was no reference to surfaces. Any idea how I can graphically display the results of analysis?

Hi Jawad, you may have resolved this problem by now but just to update on this topic, I was having the same issue with the ladybug for Dynamo 0.1.3 release and I simply connected the output from the ladybug node Color Surface to Dynamo’s Display.BySurfaceColors and input the list of surfaces into Display.BySurfaceColors…hope this helps.

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Hello everyone,
I am facing a problem in using solar analyst node in Dynamo. When I am applying the node on some surfaces (not all surfaces), the number of cumulative radiation points do not match the number of calculation points. For instance, as you can see in the screenshot, while there are 800 radiation points, there are only 420 calculation points.
I was wondering if anyone faced this issue or has a solution for it.

@Negar.s this is not a ladybug node. You will have a much better chance to get an answer id you open a new discussion and tag the right package.

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