Creating Field Calculator Expression

[WahajHabib]

Hi, I want to project population from an old census report.....the formula is as follows

   population*(1+(growth rate/100))^16

I am trying this expression for calculating from attribute table but ITS NOT WORKING

  [POP_B_SEX]*(1+ (4.33 / 100 ))Exp (16 )

Note : [POP_B_SEX] is the only column i am using from attribute table.

[DanPatterson_Retired]

Exponents aren't ^, they are **

[WahajHabib]

Yes but you see in the expression i am using "exp()"...wont they work?? and i tried with ** and doesn't work either....i guess there is something wrong with the expression....

[Pieter_Geertvan_den_Beukel]

Exp(16) means e^16 = 2.718282^16 = 8886111

You can simply use the ^ sign as in the formula.

Note: there is a difference between:

[POP_B_SEX]*(1+ (4.33 / 100 ))^16

and

([POP_B_SEX]*(1+ (4.33 / 100 )))^16

[WahajHabib]

Yeah i tried with ^ already but it doesn't work

[Pieter_Geertvan_den_Beukel · Accepted solution]

The formula works for me....

Go in ArcMap to the Geoprocessing menu and click Geoprocessing Results. What is the error message that the Field Calculator returns?

To make the formula more simple:

(1+ (4.33 / 100 ))^16 = 1.97037

Your formula can be rewritten as:

[POP_B_SEX]*1.97037

[WahajHabib]

Yes it worked i had an extra square bracket..thanks