Bug in cross product operation order

hjbortol shared this problem 1 year ago
In Progress

In the attached construction, define

R = 1/2 E + 1/2 F + ((1/2 - 1/(2 ϕ))) (H - E) + (1/(2 ϕ)) Cross(F - E, H - E) /L


The properties of R gives:

1 / 2 * E + 1 / 2 F + (1 / 2 - 1 / (2ϕ)) (H - E) + 1 / (2ϕ) F - E ⊗ H - E / L


Notice that it should be


1 / 2 * E + 1 / 2 F + (1 / 2 - 1 / (2ϕ)) (H - E) + 1 / (2ϕ) (F - E) ⊗ (H - E) / L


The missing parentheses are important: if you save the construction and reload it again, the former definition (1 / 2 * E + 1 / 2 F + (1 / 2 - 1 / (2ϕ)) (H - E) + 1 / (2ϕ) F - E ⊗ H - E / L) is used instead the correct one (1 / 2 * E + 1 / 2 F + (1 / 2 - 1 / (2ϕ)) (H - E) + 1 / (2ϕ) (F - E) ⊗ (H - E) / L).

Comments (1)

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Thanks, we'll fix that soon!


You can work around it by defining intermediate variables for F - E and H - E

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