Sky dome diffuse sum not matching weather data

[farhang.tahmasebi]

If somebody interested, I got my answer here:

Sky matrix containing horizontal irradiation

Hi Nils, Apology for not writing your name right the first time. As the hint on directNormalRadiation says, it is the radiation received on a surface perpendicular to the sun ray coming from the skydome. Therefore, only direct normal radiation should match, as you pointed out. globalHorizontalRadiation and diffuseHorizontalRadiation are radiation on a horizontal surface, so they will differ. Attached image should give you a clue. You can test this using Ladybug. Take the total of globalHoriz…