DIFFERENCE OF INTERQUARTILE RANGE

DIFFERENCE OF INTERQUARTILE RANGE (LET)

Let Subcommand

Compute the difference between the interquartile ranges for two response variables.

The interquartile range is:
IQ = UPPER QUARTILE - LOWER QUARTILE

That is, it is the difference betweeen the 75th and 25th percentiles of a variable.

For the differeence of interquartile ranges, the interquartile range is computed for each of two samples then their difference is taken.

LET <par> = DIFFERENCE OF INTERQUARTILE RANGE <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 interquartile ranges is stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

LET A = DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2
LET A = DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 SUBSET X > 1

The difference of interquartile ranges statistic is also supported for the following commands:
DIFFERENCE OF INTERQUARTILE RANGE PLOT Y1 Y2 X
CROSS TABULATE DIFFERENCE OF INTERQUARTILE RANGE PLOT Y1 Y2 X
BOOTSTRAP DIFFERENCE OF INTERQUARTILE RANGE PLOT Y1 Y2
TABULATE DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 X
CROSS TABULATE DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 X
LET Z = CROSS TABULATE DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 X1 X2


Enter

HELP STATISTIC PLOT
HELP CROSS TABULATE PLOT
HELP BOOTSTRAP PLOT
HELP TABULATE
HELP CROSS TABULATE
HELP CROSS TABULATE (LET)


for more information on these plots and commands.

None

IQ RANGE is a synonym for INTERQUARTILE RANGE

INTERQUARTILE RANGE	= Compute the interquartile range.
RANGE	= Compute the range.
MIDRANGE	= Compute the midrange.
PERCENTILE	= Compute a percentile.
QUANTILE	= Compute a quantile.
STANDARD DEVIATION	= Compute the standard deviation.
DIFFERENCE OF RANGE	= Compute the difference of the range.
DIFFERENCE OF MIDRANGE	= Compute the difference of the midrange.
DIFFERENCE OF SD	= Compute the difference of standard deviations.
DIFFERENCE OF QUANTILE	= Compute the difference of a quantile.
STATISTICS PLOT	= Generate a statistic versus subset plot.
CROSS TABULATE PLOT	= Generate a statistic versus two subsets plot.
BOOTSTRAP PLOT	= Generate a bootstrap plot.
TABULATE	= Perform a tabulation for a specified statistic.
CROSS TABULATE	= Perform a cross tabulation for a specified statistic.

Data Analysis

3/2003

SKIP 25 
READ IRIS.DAT Y1 TO Y4 X 
. 
LET A = DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 
TABULATE DIFFERENCE OF INTERQUARTILE RANGE Y1 Y2 X 
. 
XTIC OFFSET 0.2 0.2 
X1LABEL GROUP ID 
Y1LABEL DIFFERENCE OF IQ RANGES
CHAR X 
LINE BLANK 
DIFFERENCE OF INTERQUARTILE RANGE PLOT Y1 Y2 X 
CHAR X ALL 
LINE BLANK ALL 
BOOTSTRAP DIFFERENCE OF INTERQUARTILE RANGE PLOT Y1 Y2 X  
    

Dataplot generated the following output.

       ********************************************
       **  LET A = DIFFERENCE OF IQ RANGE Y1 Y2  **
       ********************************************
  
  
 THE COMPUTED VALUE OF THE CONSTANT A             =  0.72499990E+00
  
  
       ***********************************************
       **  TABULATE DIFFERENCE OF IQ RANGE Y1 Y2 X  **
       ***********************************************
  
  
                 *    Y1       AND Y2
     X           *    DIFFERENCE OF INTERQUARTILE RA
 **********************************************
     1.00000     *   -0.175001
     2.00000     *    0.200000
     3.00000     *    0.450000
  
       GROUP-ID AND STATISTIC WRITTEN TO FILE DPST1F.DAT