exp_integral_e1( z )
The exponential integral E1 of z in SageMath. Defined by
\[ E_1 (z) = \int_z^\infty du \: \frac{ e^{ -u } }{ u } \]Relation to exp_integral_ei for x > 0 :
\[ E_1 (x) = - \operatorname{Ei}(-x) \]Alias of exp_integral_e( 1 , z ).
Plot on the real axis:
Series expansion about unity:
Special values:
Related functions: exp_integral_e exp_integral_ei
Function category: exponential integrals sagemath-docs