I repeatedly run into problems where Sage claims it's not able to evaluate a function. Often, this happens due to a
ValueError: negative number cannot be raised to a fractional power which bubbles up from somewhere deep in the call stack. Here is one of those cases summand = summand*( m*( y_i-( nonpole[ _sage_const_0 ]-y_0 )/m ) )**nonpole[ _sage_const_1 ] ValueError: negative number cannot be raised to a fractional power Here is the complete code, which is a bit lengthy, though: http://alpha.sagenb.org/home/pub/698/ Could anyone clarify what exactly causes Sage to throw that error? I guess it has to do with the fields of the involved operands, however, I cannot reproduce the problem if I do something as simple as ( (-3)**(1/4) ).n( ) Thanks in advance -- You received this message because you are subscribed to the Google Groups "sage-devel" group. To unsubscribe from this group and stop receiving emails from it, send an email to sage-devel+unsubscr...@googlegroups.com. To post to this group, send email to sage-devel@googlegroups.com. Visit this group at http://groups.google.com/group/sage-devel?hl=en. For more options, visit https://groups.google.com/groups/opt_out.
