[b]Standard Deviation formula advice[/b]

[Jimdeb03]

I'm trying to calculate standard deviation on a list of fields without much luck in CR version 9

The Report Fields are...
{Samp_Data.SD_1}
{Samp_Data.SD_2}
{Samp_Data.SD_3}
{Samp_Data.SD_4}
{Samp_Data.SD_5}

Crystals StdDev function asks for a valid database or formula field so I tried summing all the above fields in Formula Field 'SumSamp' as...

"({Samp_Data.SD_1}+{Samp_Data.SD_2}+{Samp_Data.SD_3}+{Samp_Data.SD_4}+{Samp_Data.SD_5}"

So in another formula field 'SampDataSTDEV' is the formula
StdDev (@SampDataArray})

...which returns zero

Any suggestions?

And, are there any special circumstances to be aware of when choosing either Crystal or Basic Syntax in the Formula Editor?

 

[midearth]

Try enclosing your fields in brackets and separated by commas such as:

StdDev([{Samp_Data.SD_1},{Samp_Data.SD_2},{Samp_Data.SD_3},etc])

That should do the trick. Summing fields will always return zero since you're trying to return the standard deviation of a single value in that case.

 

[Madawc]

Crystal 8.5 includes Standard Deviation as one option for Running Totals, along with Count, Sum, Average etc. It should be at least as good in Crystal 9.

Madawc Williams (East Anglia)