Division by zero error in Maple about p4 HOT 3 CLOSED

Backtrace of error: (both L1 and L2 in manifold are computed as 0.

[type.tex:467] in manifold():
    lambda := coeff(collect( subs(y=0,vf2),x),x,k) / (L1*k-L2);

[infinity.tex:527] in saddle_inf():
        sep := manifold( h, taylor_level, stable );

[infinity.tex:668] in type_inf():
    saddle_inf( f, chart, x0, L1, b, L2, sdegree );

[infinity.tex:411] in find_inf_roots():
    type_inf( f_U1, 1, gn[j], t1, t2, t3, sdegree );

[infinity.tex:120] in vec_field_diff_chart(): 
    find_inf_roots( d, f, f_U1, f_U2, x, y, sdegree )

[main.tex:389] in p4main():
    vec_field_diff_chart(user_f, x, y);

from p4.

If we comment out the line infinity.tex:515 and replace it by h:=g (without 1000-time-normalisation) the computations carry out and are able to finish without error.

However, P4 is unable to plot the results due to misread type of singularity. This issue appears to be related to the develop_p5 branch, since the release_candidate version can plot the VF, but gets stuck when plotting all separatrices

from p4.

Patched with a check: if the linear parts are zeroed after normalisation just use the original vector field instead of the normalised one. Commit d7776f3

from p4.