 Dataplot Vol 2 Vol 1

# DIFFERENCE OF MEAN

Name:
DIFFERENCE OF MEAN (LET)
Type:
Let Subcommand
Purpose:
Compute the difference between the means for two response variables.
Description
The mean is computed as

$$\bar{x} = \frac{\sum_{i=1}^{n}{x_i}}{n}$$

For the difference of means, the mean is computed for each of two samples then their difference is taken.

Syntax:
LET <par> = DIFFERENCE OF MEAN <y1> <y2>
<SUBSET/EXCEPT/FOR qualification>
where <y1> is the first response variable;
<y2> is the first response variable;
<par> is a parameter where the computed difference of the means is stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.
Examples:
LET A = DIFFERENCE OF MEAN Y1 Y2
LET A = DIFFERENCE OF MEAN Y1 Y2 SUBSET X > 1
Note:
Dataplot statistics can be used in a number of commands. For details, enter

Default:
None
Synonyms:
None
Related Commands:
 MEAN = Compute the mean. DIFFERENCE OF MEDIAN = Compute the difference of medians. DIFFERENCE OF TRIMMED MEAN = Compute the difference of trimmed means. DIFFERENCE OF MIDMEAN = Compute the difference of midmeans. DIFFERENCE OF BIWEIGHT LOCATION = Compute the difference of biweight locations. STATISTICS PLOT = Generate a statistic versus subset plot. BOOTSTRAP PLOT = Generate a bootstrap plot. TABULATE = Perform a tabulation for a specified statistic.
Applications:
Data Analysis
Implementation Date:
2003/03
Program:
SKIP 25
READ IRIS.DAT Y1 TO Y4 X
.
LET A = DIFFERENCE OF MEAN Y1 Y2
TABULATE DIFFERENCE OF MEAN Y1 Y2 X
.
XTIC OFFSET 0.2 0.2
X1LABEL GROUP ID
Y1LABEL DIFFERENCE OF MEANS
CHAR X
LINE BLANK
DIFFERENCE OF MEAN PLOT Y1 Y2 X
CHAR X ALL
LINE BLANK ALL
BOOTSTRAP DIFFERENCE OF MEAN PLOT Y1 Y2 X

Dataplot generated the following output.
       ****************************************
**  LET A = DIFFERENCE OF MEAN Y1 Y2  **
****************************************

THE COMPUTED VALUE OF THE CONSTANT A             =  0.27860000E+01

*******************************************
**  TABULATE DIFFERENCE OF MEAN Y1 Y2 X  **
*******************************************

*    Y1       AND Y2
X           *    DIFFERENCE OF MEANS
**********************************************
1.00000     *     1.57800
2.00000     *     3.16600
3.00000     *     3.61400

GROUP-ID AND STATISTIC WRITTEN TO FILE DPST1F.DAT NIST is an agency of the U.S. Commerce Department.

Date created: 03/21/2003
Last updated: 11/09/2015