SED navigation bar go to SED home page go to Dataplot home page go to NIST home page SED Home Page SED Staff SED Projects SED Products and Publications Search SED Pages
Dataplot Vol 2 Vol 1

WEIGHTED SUM

Name:
    WEIGHTED SUM (LET)
Type:
    Let Subcommand
Purpose:
    Compute the weighted sum of a variable.
Description:
    The weighted sum is defined as

      WS = SUM[i=1 to N][W(i)*X(i)]

    where X is the response variable and W is the weights variable. The response variable and weights variable must have the same number of observations.

    For this command, the weights are not normalized. However, at least one of the weights must be positive and none of the weights can be negative. Otherwise, an error message is reported.

Syntax:
    LET <par> = WEIGHTED SUM <x> <w>
                            <SUBSET/EXCEPT/FOR qualification>
    where <x> is the response variable;
                <w> is the weights variable;
                <par> is a parameter where the weighted sum is saved;
    and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
    LET A = WEIGHTED SUM Y1 WEIGHT
    LET A = WEIGHTED SUM Y1 WEIGHT SUBSET Y1 > 0
Note:
    Dataplot statistics can be used in a number of commands. For details, enter

Default:
    None
Synonyms:
    None
Related Commands: Applications:
    Data Analysis
Implementation Date:
    2012/06
Program:
     
    LET Y = DATA 2 3 5 7 11 13 17 19 23
    LET W = DATA 1 1 0 0 4 1 2 1 0
    .
    LET A = WEIGHTED SUM Y W
        
    The returned value is 115.

Date created: 06/29/2012
Last updated: 06/29/2012
Please email comments on this WWW page to alan.heckert@nist.gov.