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BESSELY in WPS Spreadsheet: Bessel Y and Neumann Values

Engineering Intermediate WPS Spreadsheet

Evaluate WPS BESSELY with positive arguments, retain negative values and distinguish the second-kind Y function from modified Bessel kernels.

Verification status: See the evidence and test scope described in this guide. How formula examples are checked

Quick answer: =BESSELY(1,1) has independent expected value -0.7812128213. BESSELY evaluates the ordinary Bessel function of the second kind, Yₙ(x), also called the Neumann or Weber function.

Syntax and inputs

=BESSELY(x,n)

Both arguments are required. x is the numeric argument and n is the order. Supply the order explicitly; it is not an optional precision setting. The lesson says noninteger orders are truncated, but the reproducible examples below use positive integers, avoiding dependence on truncation and borderline inputs.

Use positive x for this worked table. It is a deliberately small domain for comparing the documented kernel, not a certification of extreme-argument accuracy or all real inputs. A Bessel value is a real numeric result here, not complex text.

Build a two-order worksheet

  1. In a fresh sheet, put x, Order and Result in A1:C1.
  2. Enter the numeric x and order values below in columns A and B.
  3. Enter =BESSELY(A2,B2) in C2. Copy it down through C5, keeping both references relative.
  4. Compare the results with these independently calculated reference values; round only for display.
Row A: x B: order Formula in C, preceded by = Expected value
2 1 1 BESSELY(A2,B2) -0.7812128213
3 2 1 BESSELY(A3,B3) -0.1070324315
4 1 2 BESSELY(A4,B4) -1.6506826068
5 2 2 BESSELY(A5,B5) -0.6174081042

Rows 2 and 3 hold the order fixed while changing x. Rows 2 and 4 hold x fixed while changing the order. This separates two effects that would be mixed together if every input changed at once. The first row also agrees mathematically with the literal formula in the quick answer.

Interpreting this particular kernel

The negative results in this table are valid signed function values. Taking an absolute value would change the mathematical quantity. Y is not a probability and is not interchangeable with J, I or K.

The lesson identifies Weber/Neumann terminology and prints the limiting relationship involving Jᵥ(x), J₋ᵥ(x), cosine and sine. Although its image heading loosely says modified, the equation and displayed Y values identify the ordinary second-kind kernel. At x = 2.5 and order 2, its walkthrough displays approximately −0.381335848. Independent evaluation gives approximately −0.381335849242, so retain the independently calculated table values when checking precision.

Advanced check: compare values without changing their meaning

Compare Y₁ at x = 2 with Y₁ at x = 1 by subtraction. The difference is approximately 0.6741803898: the function becomes less negative between these points. This positive change does not mean either endpoint value is positive. Keep signed values when inspecting zero crossings or combining prescribed basis functions.

Keep the original x and order beside every result. A chart of just the output column loses the distinction between changing the argument and changing the order. If you build a larger grid, use one row per x and one column per order, then check several individual cells against explicit literal formulas before interpreting a trend.

Errors and domain limits

The official lesson documents #VALUE! for a nonnumeric x or order, and #NUM! for a negative order. Thus =BESSELY("bad",1) and =BESSELY(1,-1) are documentation-based error expectations, not executed error captures.

The examples do not establish how numeric-looking text, blank cells, logical values or existing spreadsheet errors are coerced. Do not infer the error returned at zero or negative x from another spreadsheet program. The K and Y mathematical families have singular behavior near zero, so their positive-input examples must not be extrapolated across that boundary.

Use a function because its mathematical definition matches the intended calculation, not merely because its name contains “Bessel.” These four names describe different kernels, not legacy aliases. The lesson alone provides no broad precision, overflow, underflow or large-order guarantee.

Evidence and version scope

The official WPS Academy BESSELY lesson, published 2019-06-24, was rechecked on October 19, 2026. The lesson explicitly labels WPS Office for Windows Personal. The publication date is evidence that the function was documented by that date, not its introduction date. Exact numeric builds, first and last supported versions remain unknown. The lesson does not establish retirement or deprecation, or parity across platforms and editions.

These are original documentation-based examples with independently calculated expected values. They were not executed in WPS. Vendor demonstrations are historical documentation, not our application tests. Display rounding, client precision and workbook interchange remain unverified; the extra digits in this guide are mathematical reference values. English function names and comma separators follow the lesson.

  • BESSELI: compare the distinct mathematical kernel.
  • BESSELJ: compare the distinct mathematical kernel.
  • BESSELK: compare the distinct mathematical kernel.