TABLE_UNBORDER
Remove boundary values from a table

TABLE_UNBORDER is a C++ program which removes boundary values from a table.

To understand what's going on, assume that we begin with a set of (scalar) values on an M by N grid; we illustrate with M = 5 and N = 7:

        11  12  13  14  15  16  17
        21  22  23  24  25  26  27
        31  32  33  34  35  36  37
        41  42  43  44  45  46  47
        51  52  53  54  55  56  57
      

Suppose, for some reason, that we only want to consider the data in the "interior" of the grid; that is, we want the M-2 by N-2 array created by removing the first and last rows and columns. For our example, this would be:

        22  23  24  25  26
        32  33  34  35  36
        42  43  44  45  46
      

The TABLE_UNBORDER program is designed to do this, using the command line.

Now we are probably going to be dealing with much larger sets of data, stored in a file. So we have to figure out the rules for doing that.

Input file format: The initial data, which is "really" an M by N array, is to be thought of as a vector of length M * N, created by listing the first column, the second column, and so on to the last column. This data is stored in a file using the TABLE format. Our example data would be:

        # Comments are OK in a file if preceded by the comment character!
        #
        11
        21
        31
        41
        51
        12
        22
        ...
        27
        37
        47
        57
      

(Pie in the Sky): In a future version of this program, the data at each node will be allowed to be vector-valued. That's one reason we are forcing the data currently to be listed with just a single value per line in the file!

Usage:

table_unborder u.txt v.txt 5 7

reads the file u.txt containing a matrix of 5 rows and 7 columns, and removes the "border" values, writing the result to v.txt.

table_unborder

will prompt interactively for the four missing arguments.

Licensing:

The computer code and data files described and made available on this web page are distributed under the GNU LGPL license.

Languages:

TABLE_UNBORDER is available in a C++ version and a FORTRAN90 version.

Related Data and Programs:

TABLE, a data format which is used for the input and output of TABLE_UNBORDER.

TABLE_BORDER, a C++ program which can be used to add a border (of zero values) to a table file.

TABLE_DELAUNAY, a C++ program which reads a file of 2d point coordinates and computes the Delaunay triangulation.

TABLE_IO, a C++ library which can read or write a TABLE file.

TABLE_LATINIZE, a C++ program which can read a TABLE file and write out a "latinized" version.

TABLE_QUALITY, a C++ program which can read a TABLE file and print out measures of the quality of dispersion of the points.

TABLE_VORONOI, a C++ program which can read a TABLE file describing a set of 2D points, and print out information describing the Voronoi diagram of those points.

Source Code:

• table_unborder.cpp, the source code.
• table_unborder.sh, commands to compile and load the source code.

Examples and Tests:

Our test files are the results of the command:

table_unborder u_01.txt v_01.txt 7 5

• u_01.txt, input file #1, 7 by 5.
• u_02.txt, input file #2.
• u_03.txt, input file #3.
• v_01.txt, output file #1, 5 by 3.
• v_02.txt, output file #2.
• v_03.txt, output file #3.

List of Routines:

• MAIN is the main program for TABLE_UNBORDER.
• CH_CAP capitalizes a single character.
• CH_EQI is true if two characters are equal, disregarding case.
• CH_IS_DIGIT returns TRUE if a character is a decimal digit.
• CH_TO_DIGIT returns the integer value of a base 10 digit.
• DTABLE_DATA_BORDER_CUT cuts the "border" of double precision table data.
• DTABLE_DATA_READ reads the data from a real TABLE file.
• DTABLE_DATA_WRITE writes data to a real TABLE file.
• DTABLE_HEADER_READ reads the header from a real TABLE file.
• DTABLE_HEADER_WRITE writes the header of a real TABLE file.
• DTABLE_PRINT prints a double precision matrix, with an optional title.
• DTABLE_PRINT_SOME prints some of a double precision matrix.
• DTABLE_WRITE writes information to a real TABLE file.
• FILE_COLUMN_COUNT counts the number of columns in the first line of a file.
• FILE_EXIST reports whether a file exists.
• FILE_NAME_INC generates the next file name in a series.
• FILE_ROW_COUNT counts the number of row records in a file.
• I4_HUGE returns a "huge" integer value, usually the largest legal signed int.
• I4_INPUT prints a prompt string and reads an integer from the user.
• I4_MAX returns the maximum of two integers.
• I4_MIN returns the smaller of two integers.
• R8_EPSILON returns the R8 round off unit.
• S_LEN_TRIM returns the length of a string to the last nonblank.
• S_TO_I4 reads an integer value from a string.
• S_TO_R8 reads an R8 from a string.
• S_TO_R8VEC reads an R8VEC from a string.
• S_WORD_COUNT counts the number of "words" in a string.
• TIMESTAMP prints the current YMDHMS date as a time stamp.
• TIMESTRING returns the current YMDHMS date as a string.

You can go up one level to the C++ source codes.