CHARACTER VARIABLE (SET)

CHARACTER VARIABLE (SET)

Subcommand under SET

Specify whether the READ command and the LET ... = STRING VARIABLE command will overwrite the contents of the "dpzchf.dat" file or append new character variables to the current contents of "dpzchf.dat".

Dataplot primarily works with numeric data. However, there is limited support for character variables. Note that since character variables have limited use in Dataplot, they are not saved in memory as are numeric variables. Instead, they are written to the file "dpzchf.dat".

Dataplot has two commands for creating character variables. If the SET CONVERT CHARACTER command is set to ON or CATEGORICAL, then the READ command will parse character variables and save them to the file "dpzchf.dat". The LET ... = STRING VARIABLE command can create a character variable from a list of pre-defined strings (or literal text enclosed in quotes). This command will also save the character variable to "dpzchf.dat".

By default, either of these commands will overwrite the current contents of "dpzchf.dat". However, you can request that the new character variables be appended to the current contents of "dpzchf.dat" instead.

Typically, the append option is most likely to be used with the LET ... = STRING VARIABLE command.

SET CHARACTER VARIABLE <OVERWRITE/APPEND>
where OVERWRITE specifies that the current contents of "dpzchf.dat" will be overwritten and APPEND specifies that the new character variables will be appended to the current contetns of "dpzchf.dat".

SET CHARACTER VARIABLE OVERWRITE
SET CHARACTER VARIABLE APPEND

The "dpzchf.dat" file is simply an ASCII file. Its contents look something like (this is the file created in the Program example below)

    
 
              3
       IX               3
       IY               3
       IW               4
       Row_1                    xxxxx                    aaaa
       Row_2                    yyyyy                    bbbb
       Row_3                    zzzzz                    cccc
                                                         dddd
    
 
    

The first row specifies the number of character variables in the file. The next several rows identify the variable name and the number of rows for that character variable. The remaining rows contain the contents for the character variables. Character variables currently have a maximum length of 24 characters.

OVERWRITE

None

READ	=	Carries out a column-wise input of data.
STRING VARIABLE	=	Create a character variable from a list of previously defined strings.

Input/Output

2020/01

 
rm dpzchf.dat
set convert character on
read ix iy
Row_1   xxxxx
Row_2   yyyyy
Row_3   zzzzz
end of data
list dpzchf.dat
pause
    

The following output is generated

 
       2
IX               3
IY               3
Row_1                    xxxxx
Row_2                    yyyyy
Row_3                    zzzzz
    

 
.
set character variable append
read iw
aaaa
bbbb
cccc
dddd
end of data
list dpzchf.dat
    

The following output is generated

 
       3
IX               3
IY               3
IW               4
Row_1                    xxxxx                    aaaa
Row_2                    yyyyy                    bbbb
Row_3                    zzzzz                    cccc
                                                  dddd