Error in SERIESSUM

T

Thermal manager

The function SERIESSUM(X,n,m,Coefficients) gives an error for X=0
How to solve it, the function is useless as it is?
 
B

Bernie Deitrick

Thermal,

0 raised to any power is still 0, so you could simply use

=IF(ISERROR(SERIESSUM(X,n,m,Coefficients)),0,SERIESSUM(X,n,m,Coefficients))

HTH,
Bernie
MS Excel MVP
 
H

Harlan Grove

Bernie Deitrick wrote...
0 raised to any power is still 0, so you could simply use
Click to expand...

Only true for positive powers. For n < 0, 0^n should give #DIV/0!, and
0^0 is correctly undefined. However, in the context of SERIESSUM, X^0
should always be ignored and that term always treated as just the
[constant] coefficient.
=IF(ISERROR(SERIESSUM(X,n,m,Coefficients)),0,SERIESSUM(X,n,m,Coefficients))
Click to expand...

Not a general workaround. If n+k*m = 0 for some integer k, 0 <= k <
COUNT(Coefficients), then SERIESSUM should return the corresponding
[constant] coefficient when X = 0. So this should be

=IF(X=0,SUMPRODUCT(--(n+m*(ROW(INDIRECT("1:"&COUNTA(Coefficients)))-1)=0),
Coefficients),SERIESSUM(X,n,m,Coefficients))
 
T

Thermal manager

Well, I really think this is an error Microsoft should solve, the coder of
this function should be ashamed of such an error. In the mean time I improved
the function below to:
 
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