MERGE

MERGE (LET)

Library Function

Merge two values based on the value of a tag value.

Given values Y1 and Y2 and a tag value TAG, the merged value is Y1 if TAG = 0 and Y2 if TAG = 1.

Note that any value of TAG less than or equal to 0 will be treated as a 0 and any value of TAG that is greater than 0 will be treated as a 1.

There is an alternate version of this command (see Syntax 2) that selects one of three values depending on whether the value of TAG is negative, zero, or positive.

LET <y> = MERGE(<y1>,<y2>,<tag>)
                  <SUBSET/EXCEPT/FOR qualification>
where <y1> is a variable or a parameter;
            <y2> is a variable or a parameter;
            <tag> is a variable or a parameter;
            <y> is a variable or a parameter (depending on what <y1>, <y2>, and <tag> are) where the computed merged values are stored; and where the <SUBSET/EXCEPT/FOR qualification> is optional.

LET <y> = MERGE3(<y1>,<y2>,<y3>,<tag>)
                  <SUBSET/EXCEPT/FOR qualification>
where <y1> is a variable or a parameter;
            <y2> is a variable or a parameter;
            <y3> is a variable or a parameter;
            <tag> is a variable or a parameter;
            <y> is a variable or a parameter (depending on what <y1>, <y2>, <y3>, and <tag> are) where the computed merged values are stored;
and where the <SUBSET/EXCEPT/FOR qualification> is optional.

LET A = MERGE(14,10,1)
LET A = MERGE(14,10,0)
LET A = MERGE(A1,A2,TAG)
LET X2 = MERGE(X1,X4,TAG)
LET Y = MERGE3(X1,X2,X3,TAG)

If more than one argument is a variable, the variables must be the same length.

This command is distinct from the MERGE LET sub-command.

None

None

MERGE	= Merge two data sets.
RELDIF	= Compute the relative difference of two numbers.
RELERR	= Compute the relative error of two numbers.
PERCDIF	= Compute the percent difference of two numbers.
PERCERR	= Compute the percent error of two numbers.
MIN	= Compute the minimum of two numbers.
MAX	= Compute the maximum of two numbers.
ABS	= Compute the absolute value of a number.

Data Management

2010/12

 
let y1 = sequence 1 1 20
let y2 = sequence -1 -1 -20
let y3 = 0 for i = 1 1 20
let tag = sequence 0 1 1 for i = 1 1 20
let tag2 = sequence -1 1 1 for i = 1 1 20
.
let yout = merge(y1,y2,tag)
set write decimals 1
print yout
    

The following output is printed:

---------------
           YOUT
---------------
            1.0
           -2.0
            3.0
           -4.0
            5.0
           -6.0
            7.0
           -8.0
            9.0
          -10.0
           11.0
          -12.0
           13.0
          -14.0
           15.0
          -16.0
           17.0
          -18.0
           19.0
          -20.0
    

let yout = merge3(y1,y2,y3,tag2)
set write decimals 1
print yout
    

The following output is printed:

---------------
           YOUT
---------------
            1.0
           -2.0
            0.0
            4.0
           -5.0
            0.0
            7.0
           -8.0
            0.0
           10.0
          -11.0
            0.0
           13.0
          -14.0
            0.0
           16.0
          -17.0
            0.0
           19.0
          -20.0