AndrewAnnex
commented
1 year ago @kconnour thanks for the issue, so the 4th parameter is a boolean "found" flag which is swallowed up by the spice_found_exception_thrower decorator which changes the effective return type of the function by returning only the first three parameters, see https://spiceypy.readthedocs.io/en/main/_modules/spiceypy/spiceypy.html#spice_found_exception_thrower. This is currently the default behavior for all functions that return a "found" flag as the last parameter of the return (eg bodn2c). That does make the doc a little deceptive if you aren't aware of that behavior, but the behavior has been in spiceypy for a number of years now.
To see this you can try the call using the context manager for the checker, modifying your example like so:
target = 'Mars'
observer = 'MAVEN'
abcorr = 'LT+S'
body = 499 # Mars IAU code
frame = 'IAU_Mars'
et = 521320703.35254663
bin_vector = [0.64829554 0.20495633 0.14674814]
with spice.no_found_check():
spoint, _, _, _ = spice.sincpt('Ellipsoid', target, et, frame, abcorr, observer, frame, bin_vector)
which shouldn't raise an exception.
Likely your colleague has disabled the decorator somewhere else in their code by calling spice.found_check_off() which disables the decorator without using the context manager, or else they were just going off of the docstring directly.
I could probably think about a better way to convey the return types for these functions but let me know if my explainer above makes sense.
kconnour
Describe the bug The return value of
sincptdoesn't match the documentation... or seemingly the code strangely enough. It appears that this function should return 4 values but instead it only returns the first 3.Expected behavior I expect this function to return a tuple with 4 values: an array, a float, an array, followed by a boolean. Instead, I can only get this function to return a tuple with 3 values: an array, a float, and an array. I don't care about the boolean (or the last 2 values), but this means that this code (that I would expect to work) does not:
spoint, _, _, _ = spice.sincpt('Ellipsoid', target, et, frame, abcorr, observer, frame, bin_vector)It raises this:
ValueError: not enough values to unpack (expected 4, got 3)However, trying to unpack 3 values raises no error and the values look good.
To Reproduce
I can't tell you more about the kernels I'm using. I'm using code someone else on the team wrote to load them in and there are a few thousand of them loaded.
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