# formula for normalization

Discussion in 'Homework Help' started by strikefreedom, Apr 15, 2012.

1. ### strikefreedom Thread Starter New Member

Mar 31, 2012
7
0
i have a data given in excel sheet need to normalization, i need the formula for normalization and the range is between -1 and +1...

anyone can help me this formula...

2. ### strikefreedom Thread Starter New Member

Mar 31, 2012
7
0
3 input and 1 output

3. ### WBahn Moderator

Mar 31, 2012
17,446
4,699
What range is -1 to +1? The data in the sheet or the normalized range?

Somewhat related, but what is the data supposed to be normalized to? Are you give a reference value of some kind, or is it to be normalized to the mean? Normalized to the standard deviation? Normalized to the max, the min, the larger of the absolute values of the max and min? What?

Do you just want the formula, or information that should help you figure it out on your own?

4. ### strikefreedom Thread Starter New Member

Mar 31, 2012
7
0
thank....ok....this is the objective for this title

Project objective:
3 input: corridor width, lobby area,number of room
1 output: evacuation time
there are total 750 data samples. first 500 is used to train the system. the next 250 data sample is put into the system, output(evacuation time) is compared with the excel evacuation time to compare the error between expected output(excel sheet evacuation time) and the prediction of ELM (evacuation time get from Matlab).

What we need to do:
-normalization of data
the data given in the excel sheet need to be normalized. Pls find the formula for normalization and make sure that the range is between -1 and +1.

ELM - extreme learning Machine neural network

5. ### panic mode Senior Member

Oct 10, 2011
1,308
298
not sure what you really want but suppose you have set of numbers in Excel's A column, say A1...A20 just as an example. then you can:
- click into B1 and type =abs(max(A1:A20))
- click into B2 and type =abs(min(A1:A20))
- click into B3 and type = max(B1:B2)

this will give min and max value of the set of numbers we have there.
suppose we want to make copy of that column in column C but so that we see values normalized to -1...+1

then you could click on C1 and type
=A1/\$B\$3
highlight that cell, grab lower right corner and drag it down to C20
you will get in column C scaled version of numbers from column A such that any value is within -1..+1 range

6. ### WBahn Moderator

Mar 31, 2012
17,446
4,699
Is this exactly how the requirement was stated, or are you trying to describe it as you understand it? If the latter, could you post the actual instructions from the assignment?

I can think of a few ways to do it, but none of them jump out as being "correct" and each of them is certainly incorrect depending on what the purpose of normalizing the data, in this particular case, is.