The Excel BESSELY Function

Function Description

The Excel Bessely function returns the Bessel function, Yn(x), (also known as the Weber function or the Neumann function), for a specified order and value of x.

The syntax of the function is:

BESSELY( x, n )

where the function arguments are as follows:

x - The value at which the function is to be evaluated.
n -

A positive integer, denoting the order of the Bessel function.

(If the supplied value of n is a decimal, it is truncated to an integer by Excel).

Bessely Function Example

Chart Showing Modified Bessel Function Yn(x) of Order 1
Order 1 Bessel Function Y1(x)

The above chart on the right shows the order 1 Bessel function, Y1(x).

If you want to calculate the value of this function at x = 0.05, this can be done using the Excel formula:

=BESSELY( 0.05, 1 )

which gives the result -12.78985516.

See the Microsoft Office website for further information on the Excel Bessely function.

Bessely Function Errors

If you get an error from the Excel Bessely function this is likely to be one of the following:

Common Errors
#NUM! -

Occurs if either:

  • The supplied value of x is ≤ 0
  • The supplied value of n is < 0.
#VALUE! - Occurs if any of the supplied arguments are non-numeric.