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Dataplot Vol 1 Vol 2

READ MATRIX TO VARIABLES

Name:
    READ MATRIX TO VARIABLES
Type:
    Input Command
Purpose:
    Reads matrix data into a response variable, a row-id variable, and a column-id variable.
Description:
    The READ MATRIX command is used to read a data file into a matrix. This is useful for utilizing the Dataplot commands that explicitly work on matrices.

    However, in some cases it may be more convenient to read the matrix as a single response variable. For example, you may want to use commands that work on variables rather than matrices. In these cases, you can use the READ MATRIX TO VARIABLES command instead of the READ MATRIX command. This command will create row-id and column-id variables in addition to the response variable.

Syntax:
    READ MATRIX TO VARIABLES <file> <y> <rowid> <colid>
    where <file> is the name of the file that contains the matrix data;
                <y> is the response variable where the data will be saved;
                <rowid> is a variable that identifies the row of the matrix for each response variable;
                and <colid> is a variable that identifies the column of the matrix for each response variable.

    The <file> argument is optional. If it is omitted, Dataplot will read the matrix data from the terminal rather than a file.

Examples:
    READ MATRIX TO VARIABLES FILE.DAT Y ROW COL
Note:
    By default, DATAPLOT does free format reads. However, it has the capability for supporting FORTRAN style formats. Formatted reads can be about 10 times faster on many systems. This can be helpful for large data files. Enter HELP READ FORMAT for more details.
Note:
    Blank lines in data files are ignored.
Note:
    DATAPLOT supports the ability to embed comment lines within the data file. Enter HELP COMMENT CHECK for details.
Note:
    In order to determine whether the first argument is a file name or a variable name, it looks for a period in the name. If it finds one, it assumes a file name. If it does not, it assumes a variable name. If your file name does not contain a period, attach a trailing period (no spaces) to the file name on the READ STACKED VARIABLES command.
Note:
    DATAPLOT has no restrictions on the file name other than it be a valid file name on the local operating system and that it contain a period "." in the file name itself or as a trailing character. DATAPLOT strips off trailing periods on those systems where it is appropriate to do so. On systems where trailing periods can be a valid file name (e.g., Unix), DATAPLOT tries to open the file with the trailing period. If this fails, it then tries to open the file with the trailing period stripped off.

    Some users prefer to give all data files a ".DAT" or ".dat" extension. Although this is a useful method for keeping track of data files, it is strictly a user convention and is not enforced by DATAPLOT in any way.

Note:
    File names are case sensitive on Unix file systems. For Unix, DATAPLOT attempts to open the file as given. If this fails, it attempts to open the file as all upper case characters. If this fails, it attempts to open the file as all lower case characters. All other currently supported systems are not case sensitive regarding file names.

    As a further caution for Unix hosts, certain expansion characters (specifically ~ to refer to your home directory) are interpreted by the shell and are not recognized by the Fortran compiler. These expansion characters are interpreted as literal characters and do not yield the intended file name.

Default:
    None
Synonyms:
    None
Related Commands: Applications:
    Data Input
Implementation Date:
    2009/1
Program:
     
    READ MATRIX TO VARIABLES Y ROWID COLID
    1 3 2
    7 3 1
    8 1 2
    END OF DATA
    PRINT Y ROWID COLID
        

    The following output results for Y, ROWID and COLID:

     
    1  1  1
    3  1  2
    2  1  3
    7  2  1
    3  2  2
    1  2  3
    8  3  1
    1  3  2
    2  3  3
        

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Date created: 01/12/2009
Last updated: 11/04/2015

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