SCATTER

SCATTER (LET)

Let Subcommand

Save rows of a variable based on index values contained in another variable.

The GATHER command (HELP GATHER for details) can be used to extract specific rows of a variable based on an index variable.

The SCATTER command is most often used after a GATHER command. That is, we use GATHER to extract specific rows of a variable, perform operations that modify these extracted values, and then use SCATTER to save these modfied values back in the original variable.

LET <y> = SCATTER <x> <index>
where <x> is a response variable;
            <index> is a variable containing row numbers;
            and <y> is a variable where the values of <x> will be saved.

LET Y = SCATTER X INDEX

None

None

GATHER	= Extract specified rows of data from a variable
SEQUENCE	= Generate a patterned sequence of values.
SORT	= Sort a column of numbers.
RANK	= Rank a column of numbers.
CODE	= Code a column of numbers.
SUBSET	= Specifies a subset to be included in a plot, analysis, or LET command.
RETAIN	= Retain specified rows or a subset of a variable.

Data Transformation

2008/11

 
let n = 30
let xseq = sequence 1 1 n
let x = normal rand numb for i = 1 1 n
let iindex = data 10  14  8  23  19
.
let y = -10 for i = 1 1 n
let y = scatter x iindex
set write decimals 3
print xseq  x  y iindex
    

The following output is generated.

          1.000         -1.073        -10.000         10.000
          2.000          0.573        -10.000         14.000
          3.000         -0.873        -10.000          8.000
          4.000          0.234        -10.000         23.000
          5.000         -0.455        -10.000         19.000
          6.000         -0.525        -10.000          0.000
          7.000         -0.706        -10.000          0.000
          8.000          0.032         -0.873          0.000
          9.000          1.191        -10.000          0.000
         10.000          0.270         -1.073          0.000
         11.000         -0.149        -10.000          0.000
         12.000         -0.197        -10.000          0.000
         13.000         -0.243        -10.000          0.000
         14.000         -0.841          0.573          0.000
         15.000         -0.104        -10.000          0.000
         16.000          0.419        -10.000          0.000
         17.000          0.264        -10.000          0.000
         18.000          0.898        -10.000          0.000
         19.000          0.034         -0.455          0.000
         20.000          1.588        -10.000          0.000
         21.000          0.389        -10.000          0.000
         22.000         -0.470        -10.000          0.000
         23.000         -1.063          0.234          0.000
         24.000         -0.027        -10.000          0.000
         25.000         -0.464        -10.000          0.000
         26.000          0.592        -10.000          0.000
         27.000         -0.506        -10.000          0.000
         28.000         -0.360        -10.000          0.000
         29.000          0.499        -10.000          0.000
         30.000          0.243        -10.000          0.000