DEDUCE FILE SEQUENCE

Often it is desired to run a series of data analysis operations on a whole series of files. This can be achieved by running a macro on a whole series of files using the "SEQUENCE" command (Section 15.90, Page ), or by writing a single macro with a loop which runs on different files (see Section 30, Page ).

When a macro is to be run on a series of files, it is necessary to deduce the file sequence. i.e. the number of the first and last file in the sequence, the base part of the file name, and the file extensions. DEDUCE FILE SEQUENCE allows a starting file name and an end file name to be entered, which may of course be program variables, and if possible deduces the parameters of the sequence, and sets a number of internal program variables.

• ##PREFIX : This is a character string set to the non-changing characters at the start of the file names.

• ##START : This is an integer value from the starting file in the series

• ##END : This is an integer value from the last file in the series

• ##STEP : This is an integer value for the step from one file in the series to the next. This will normally be set to 1, or to -1 if the last file number is less than the first file number.

• ##VARIABLE : This is a logical (boolean) value (TRUE or FALSE) which tells whether or not the number of characters used to store the changing numerical part is variable or fixed. e.g. file_1.dat to file_100.dat has a variable number of characters, whereas file_001.dat to file_100.dat has a fixed number of characters.

• ##NUM_CHARS : When ##VARIABLE is FALSE this is an integer value which is the number of characters used to store the changing numerical part of the file names.

• ##POSTFIX : This is a character string with any non-changing part of the file names after the changing numerical part, but before any file extension. (Often this will be blank.)

• ##EXTENSION : This is a character string with any non-changing part of the file name after, and including the decimal point¹⁹.

e.g. If #FILE_1ST equals /users/a/smith/data/poly_001.dat and #FILE_LAST equals
/users/a/smith/data/poly_180.dat then:

Main menu: ENTER COMMAND [PLOT DATA]: DEDUCE
ENTER NAME OF STARTING FILE [fit2d_999.f2d]: #FILE_1ST
ENTER NAME OF END FILE [fit2d_001.f2d]: #FILE_LAST
Main menu: ENTER COMMAND [CONCATENATION]: LIST VARIABLES
##PREFIX = /users/a/smith/data/poly_
##START = 1
##END = 180
##STEP = 1
##VARIABLE = FALSE
##NUM_CHARS = 3
##POSTFIX =
##EXTENSION = .dat

This command is useful for creating macros which work with file series.