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Description
Describe the bug
vf_ground_sky_2d
considers one fewer sky wedge on the right side of the central wedge than it does on the left side.
To Reproduce
I added a line print(next_edge)
after here:
pvlib-python/pvlib/bifacial/utils.py
Line 170 in 7608eda
np.clip(next_edge, a_min=0., a_max=None, out=next_edge) |
Then I ran _ = vf_ground_sky_2d(surface_tilt=0, gcr=0.5, x=0.5, pitch=1, height=1, max_rows=3)
and got the printed text: [[[0.01598559 0.04556841 0.18086881 0.48507125 0.18086881 0.04556841]]]
.
Each value in that output describes the VF of a visible sky wedge. The inputs describe a symmetrical system, so the VFs should be symmetrical too, and they are, except one of them is missing... 0.485 for the wedge directly overhead, with three wedges to the left but only two to the right.
Expected behavior
I want the number of sky wedges considered in each direction to be equal.
Maybe this is a fencepost problem, and really what I want is effectively a max_wedges
parameter instead of max_rows
?
Activity
mimic original max_rows behavior (pvlib#1867)
pasquierjb commentedon Oct 17, 2023
k goes from
-max_rows
tomax_rows+1
so the symmetry is for x=0 which is indeed problematic if you intergrate betwen 0 and 1 for a smallmax_rows
. However asmax_rows
is set to be high enough to neglect the horizon VF, not sure it will change a lot the results.Sar-thak-3 commentedon Jan 7, 2024
Hi @kandersolar, is this issue still open? I would love to contribute to this issue!