READ MISSING VALUE (SET)

READ MISSING VALUE (SET)

Subcommand under SET

Specifies the value to be used when a missing value is encountered with the array form of the COLUMN LIMITS command.

The January, 2004 version of Dataplot added support for an array form of the COLUMN LIMITS command. This form is used to specify the lower and upper columns to read for each data field. One specific case this was intended to handle was data files containing columns of unequal length. This is a common occurence when Excel files are saved to ASCII data files.

When the array form of the COLUMN LIMITS comamnd is used, an empty field is interpreted as a missing value. By default, Dataplot will assign a value of zero. If you want to assign a value other than zero, use the SET READ MISSING VALUE command to specify that value.

SET READ MISSING VALUE <value>
where <value> denotes the value to assign when an empty data field is encoutered.

SET READ MISSING VALUE -999
SET READ MISSING VALUE 0
SET READ MISSING VALUE -1

This command only applies when the array form of the COLUMN LIMITS command has been invoked. Otherwise, if the number of values read is less than the number of variables specified on the READ command, Dataplot treats this as an error.

Zero

None

READ	= Carries out a column-wise input of data.
COLUMN LIMITS	= Specify what columns to read.

Input/Output

2004/1

 
SET READ MISSING VALUE -99
LET LOWLIM = DATA  1 11
LET UPPLIM = DATA 10 20
COLUMN LIMITS LOWLIM UPPLIM
READ DUMMY.DAT  Y X
PLOT Y X   SUBSET Y > -99 SUBSET X > -99