Calculating Standard Deviation

numero = 298
interpreted = N
texte = I needed to do this for one of my hobby sites, so I thought I would share. Good if you have a scoring or ratings system on your site.

make sure that you have a tab on this line as indicated: sdev[index]<tab>[math][interpret][dev[index]][/interpret]*[interpret][dev[index]][/interpret][/math]

[!]<!-- The following code will find the standard deviation-->[/!][!]<!-- in a range of numbers stored in a database (or table),  -->[/!][!]<!-- where math.db is your database of scores                -->[/!][!]<!-- SAMPLE DATABASE:rating8565497156-->[/!][!]<!--Should yield a STANDARD DEVIATION of 2.22-->[/!][search db=math.db&neRATINGdatarq=[blank]][text show=F]numscores=[numfound][/text][founditems]Rating [index]=[text show=T]num[index]=[rating][/text]<br>[/founditems]Total: [text show=T]total=[sum field=rating][/text]<br>[/search]Avg: [text show=T]avg=[math][total]/[numscores][/math][/text]<br><hr>[loop start=1&end=[numscores]][text show=f]dev[index]=[math]([Interpret][num[index]][/Interpret]-[avg])*-1[/math][/text][/loop][table name=sdev&fields=sku,sdevnum][loop start=1&end=[numscores]]sdev[index]<tab>[math][interpret][dev[index]][/interpret]*[interpret][dev[index]][/interpret][/math][/loop][/table][search table=sdev&neskudatarq=[blank]][text show=f]devsum=[sum field=sdevnum][/text]<br>[/search][text show=f]ass=[math][devsum]/([numscores]-1)[/math][/text]Standard Deviation =[format .2f][math]sqrt([ass])[/math][/format]
I needed to do this for one of my hobby sites, so I thought I would share. Good if you have a scoring or ratings system on your site.

make sure that you have a tab on this line as indicated:
sdev[index]<tab>[math][interpret][dev[index]][/interpret]*[interpret][dev[index]][/interpret][/math]



[!]<!-- The following code will find the standard deviation-->[/!]
[!]<!-- in a range of numbers stored in a database (or table), -->[/!]
[!]<!-- where math.db is your database of scores -->[/!]
[!]<!--
SAMPLE DATABASE:
rating
8
5
6
5
4
9
7
1
5
6
-->[/!]
[!]<!--Should yield a STANDARD DEVIATION of 2.22-->[/!]

[search db=math.db&neRATINGdatarq=[blank]]
[text show=F]numscores=[numfound][/text]
[founditems]
Rating [index]=[text show=T]num[index]=[rating][/text]<br>
[/founditems]
Total: [text show=T]total=[sum field=rating][/text]<br>
[/search]
Avg: [text show=T]avg=[math][total]/[numscores][/math][/text]<br>
<hr>
[loop start=1&end=[numscores]]
[text show=f]dev[index]=[math]([interpret][num[index]][/Interpret]-[avg])*-1[/math][/text]
[/loop]
[table name=sdev&fields=sku,sdevnum]
[loop start=1&end=[numscores]]
sdev[index]<tab>[math][interpret][dev[index]][/interpret]*[interpret][dev[index]][/interpret][/math]
[/loop]
[/table]
[search table=sdev&neskudatarq=[blank]]
[text show=f]devsum=[sum field=sdevnum][/text]<br>
[/search]

[text show=f]ass=[math][devsum]/([numscores]-1)[/math][/text]
Standard Deviation =[format .2f][math]sqrt([ass])[/math][/format]
Gary Krockover

DOWNLOAD WEBDNA NOW!

Top Articles:

Tips and Tricks

A list of user-submitted tips ...

WebDNA Libraries

A list of available libraries for WebDNA...

[biotype]

BioType is a behavioral biometrics WebDNA function based on ADGS research and development (from version 8...

F.A.Q

A compilation of some user's questions...

Technical Change History

This Technical Change History provides a reverse chronological list of WebDNA changes...

WebDNA Modules

A list of the currently available modules...

Related Readings:

File upload example

...

Redefining [date] & [time] to match your time zone

Your server is not always in the same time zone as your web site...

Do you hate updating the copyright notice at the bottom of all your pages?

It's January 1st and you have to update the copyright notice at the bottom of all your websites...

How to keep the text variable after a function has finished

By default...

Formatting a long list in a table

How to show the result of a search as a table...

How many working days?

This small script finds the number of working days between two dates...