AFNI program: 1dcat

Usage: 1dcat a.1D b.1D ...
where each file a.1D, b.1D, etc. is an ASCII file of numbers
arranged in rows and columns.
The row-by-row catenation of these files is written to stdout.

TIMESERIES (1D) INPUT
---------------------
A timeseries file is in the form of a 1D or 2D table of ASCII numbers;
for example:   3 5 7
               2 4 6
               0 3 3
               7 2 9
This example has 3 rows and 4 columns.  Each column is considered as
a timeseries in AFNI.  The convention is to store this type of data
in a filename ending in '.1D'.

When specifying a timeseries file to an command-line AFNI program, you
can select a subset of columns using the '[...]' notation:
  'fred.1D[5]'            ==> use only column #5
  'fred.1D[5,9,17]'       ==> use columns #5, #9, and #12
  'fred.1D[5..8]'         ==> use columns #5, #6, #7, and #8
  'fred.1D[5..13(2)]'     ==> use columns #5, #7, #9, #11, and #13
Sub-brick indexes start at 0.  You can use the character '$'
to indicate the last sub-brick in a dataset; for example, you
can select every third sub-brick by using the selection list
  'fred.1D[0..$(3)]'      ==> use columns #0, #3, #6, #9, ....
Similarly, you select a subset of the rows using the '{...}' notation:
  'fred.1D{0..$(2)}'      ==> use rows #0, #2, #4, ....
You can also use both notations together, as in
  'fred.1D[1,3]{1..$(2)}' ==> columns #1 and #3; rows #1, #3, #5, ....

You can also input a 1D time series 'dataset' directly on the command
line, without an external file. The 'filename' for such input has the
general format
  '1D:n_1@val_1,n_2@val_2,n_3@val_3,...'
where each 'n_i' is an integer and each 'val_i' is a float.  For
example
   -a '1D:5@0,10@1,5@0,10@1,5@0'
specifies that variable 'a' be assigned to a 1D time series of 35,
alternating in blocks between values 0 and value 1.