In the second line, the number one is added to the fraction, and again Excel displays only 15 figures. By using this site, you agree to the Terms of Use and Privacy Policy. If the grid is spaced very finely, round-off error will occur, and the less the precision used, the worse the round-off error. This time, you should see an error message: The error is Overflow.

However, if we show 16 decimal places, we can see that one result is a very close approximation. If you want a really, really long floating point number (a number with "point something" at the end) then use As Double, otherwise just use As Single. This option is generally not recommended unless you are sure more precision will not ever be needed for your situation. Q: What caused the bug?

The bias for double-precision numbers is 1023. The second line uses Rows.Count to get the number of rows on Worksheet 1. The number 10.4 is stored as

0100000000100100110011001100110011001100110011001100110011001100 In Hex notation, this would be 4024CCCCCCCCCCCC The first 0 is the sign bit. And let's face it -- do you really want the bright sparks who work there now, and manage to break lots of perfectly good working code -- rewriting the core calculatingFor example, suppose we have the formula =1/3 in each of the three cells A1:A3. You can help by adding to it. (April 2010) Statistical functions[edit] Error in Excel 2007 calculation of standard deviation. Truth in numbers If Dumbledore is the most powerful wizard (allegedly), why would he work at a glorified boarding school? Make sure your cursor is flashing between the Sub and End Sub of your new code.

Nor are they "bugs" in the programs. That occurs when there are no exact binary equivalents for all the numbers or for the result of the calculation. For example, a fixed-point representation that has 5 decimal digits with the decimal point positioned after the third digit can represent the numbers 123.34, 12.23, 2.45, etcâ€¦ whereas floating-point representation with If not, then the conversion will result in a rounded value which will represent the original value.

If Round(a,2) = Round(b,2) Then //code inside block will now trigger. Rather than a long explanation about MsgBox, try it out to see what it does. Single precision floating point numbers, or "singles" are similar to doubles, except that they occupy 32 bits, rather than 64 bits, and have an 8 bit exponent rather than an 11 Hamming (1986).

Depending on the nature of your problem space, you may be better off using the Decimal VBA type which can represent decimal numbers (base 10) with perfect precision up to a A guide to Microsoft Excel 2007 for scientists and engineers. Browse other questions tagged excel vba comparison double or ask your own question. Run your code again and the Message Box will display the following: Now the FloatingPoint variable is showing the answer to 10 divided by 3 to fourteen decimal places.

VBA has rounded the value up for As Single. For example, a stored value of 1000 indicates an exponent of 1000 - 1023, or -23. So, invaluable as it may be for making accurate calculations, you can rely on error-free calculation only if the values used and the true results do not extend beyond this four p.12.

Use the ROUND function to fix this. At the lower level the Integer variable type can only hold negative numbers up to -32, 768. Subtraction of Subtraction Results[edit] Doing simple subtractions may lead to errors as two cells may display the same numeric value while storing two separate values. Now change As Long to As Integer: Dim NumberOfRows As Integer Try running your Sub again.

Oxford University Press. Better worry about getting hit by a meterorite. If we subtract one from the other, we probably get something like 0.00000000051. The discrepancy indicates the error.

These are 8-byte variables that can store numbers accurate to approximately 15 decimal places. The same thing happens in binary with numbers ending in 0.1: they are repeating decimals, so when you do mathematical operations on them, very small insignificant errors creep in somewhere way If the numerical procedure is thought of as a feedback system, this calculation noise may be viewed as a signal that is applied to the system, which will lead to instability Cells containing this value display as 100,000, but from VBA, they're going to look like 65,535 (since the number would be passed into the Basic runtime in binary, before the display

To turn on this option, follow these steps: Click Microsoft Office Button -> Excel Options -> Advanced In the When calculating this workbook section, select the workbook you want, and then I haven't been there for a long time. That said, CPUs have gotten pretty fast. Round-off error[edit] User computations must be carefully organized to ensure round-off error does not become an issue.

See the on-line help for more information about these functions.