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#5763 make_elliptic_f returns wrong results for inverse cd, dc, ds

None
closed
None
5
10 hours ago
1 day ago
Raymond Toy
No

Currently:

(%i1) make_elliptic_f(inverse_jacobi_cd(x,m));
(%o1)           elliptic_f(asin(sqrt((1 - x^2) (1 - m x^2))), m)
(%i2) make_elliptic_f(inverse_jacobi_dc(x,m));
(%o2)            elliptic_f(asin(sqrt((x^2 - 1) (x^2 - m))), m)
(%i3) make_elliptic_f(inverse_jacobi_ds(x,m));
(%o3)                  elliptic_f(asin(sqrt(x^2 + m)), m)

But they should be

inverse_jacobi_cd(x,m) = elliptic_f(asin(sqrt((1-x^2)/(1-m*x^2))), m)
inverse_jacobi_dc(x,m) = elliptic_f(asin(sqrt((x^2-1)/(x^2-m))), m)
inverse_jacobi_ds(x,m) = elliptic_f(asin(1/sqrt(x^2+m)), m)

Issue found by Claude while working on inverse Jacobi functions.

Discussion

  • Raymond Toy

    Raymond Toy - 10 hours ago
    • status: open --> closed
    • assigned_to: Raymond Toy
     
  • Raymond Toy

    Raymond Toy - 10 hours ago

    Fixed by merging branch bug-5763-fix-make-elliptic-f at commit [285b41]

     

    Related

    Commit: [285b41]


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