SUBSTRING

SUBSTRING

Let Subcommand

Extract a substring of a previously defined string.

LET <sout> = SUBSTRING <sorg> <nstart> <nstop>
where <sout> is the name of the resulting string;
            <sorg> is the name of the original string;
            <nstart> is the start position in <sorg>;
and <nstop> is the stop position in <sorg>.

LET SOUT = SUBSTRING S1 NSTART NSTOP
LET SOUT = SUBSTRING S1 3 8

The name of the new string can be the same as the original string. For example,
LET FNAME = SUBSTRING FNAME NSTART NSTOP

In this case, FNAME will now contain the substring rather than the original string.

The string on the right hand side of the equal sign must be a previously existing string. That is, expressions are not allowed. For example, instead of
LET FNAME = SUBSTRING "file99.dat" 5 6

you need to do

LET STRING SORG = file99.dat
LET FNAME = SUBSTRING SORG 5 6


The start and stop position can be either a parameter or a numeric value. However, it cannot be a numeric expression. So

LET FNAME = SUBSTRING SORG 5 6
LET FNAME = SUBSTRING SORG NSTART NSTOP


are both allowed but

LET FNAME = SUBSTRING SORG NSTART NLEN/2

is not allowed. You would need to enter this as

LET NSTOP = NLEN/2
LET FNAME = SUBSTRING FNAME NSTART NSTOP

The total number of characters that DATAPLOT can use for storing functions and strings is set when DATAPLOT is built. The current default (11/2008) is 50,000 characters. Previous versions may set this limit at 1,000 or 10,000 characters. This limit applies to the combined number of characters for all functions and strings.

None

None

UPPER CASE	= Convert a string to upper case.
LOWER CASE	= Convert a string to lower case.
LET FUNCTION	= Defines a function.
LET STRING	= Defines a string.
READ STRING	= Reads a string from a file.
SUBSTITUTE CHARACTER (^)	= Substitute the value of a string or parameter.
CONCATENATE CHARACTER (&)	= Concatenate two strings.
STRING INDEX	= Extract the start/stop positions of a substring within a string.
STRING CONCATENATE	= Concatenate one or more previously defined strings.
STRING EDIT	= Edit a string.
STRING MERGE	= Insert a string into another string without overwrite.
STRING REPLACE	= Insert a string into another string with overwrite.
STRING LENGTH	= Return the length of a string.
CHARACTER	= Convert numeric values to strings based on the ASCII collating sequence.
ICHAR	= Convert a string to numeric values based on the ASCII collating sequence.
GROUP LABEL	= Define the text for group labels.

Data Management

11/2008

 
LET STRING S1 = file23.dat
LET NSTOP = STRING LENGTH S1
LET NSTART = STRING INDEX S1 SPERIOD
LET SEXT = SUBSTRING S1 NSTART NSTOP
LET NSTOP = NSTART - 1
LET NSTART = 1
LET SBASE = SUBSTRING S1 NSTART NSTOP
    

The resulting strings SEXT and SBASE will contain
.dat
file23