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  (c) TransEra Corp, 2021
Ei
Exponential integral.
 
Loading        LOADSUB ALL FROM "EI.HTS"
or LOADSUB FROM "MATHLIB.HTS"
 
Usage                REAL X,Y
Y=FNEi(X)
 
Description                
FNEi returns the value of the exponential integral of x, Ei(x). Ei(x) is defined by the relation
The integration represents the value obtained by integrating in the complex plane along a path that excludes the origin and that does not cross the negative part of the real axis. The value of Ei(x) is - at x = 0 and becomes large for large positive values of x.
 
Ei(x)
 
Errors                
FNEi causes an HTBasic error if its argument is not of type REAL or if the magnitude of Ei(x) would be greater than MAXREAL.
 
See Also
Ci, E1, Li, Si