# con2con

##

Last updated Fri Nov 19 12:57:05 1999

Convert the format of contour files

## 1. USAGE

con2con [options] [file file ... ]

## 2. DESCRIPTION

This utility converts contour files into more generalized contour files and vice versa. Contour files have usually the same format as those created by the contour product with adcpsect or xtract(1). They have typically the following columns:

1. Data for X axis
2. Data for Y axis
3. Data for Z axis

where data for the different Y grid points at the same X location appear successively. If the file has been created with

xtract(1), more than one column of data for the Z axis can be present. A more generalized contour file will contain additional X position information. This is used for example with

con2db(1), where both TIME and POSITION are required to locate a profile. In this case, the file has the following columns:

1. Time
2. Longitude
3. Latitude
4. Bin depth
5. Bin data

where several columns with different bin data can appear. This utility can be used to transform files from one format to the other.

In order to generate a more generalized contour file, one has to specify a position file with the -f option. If this option is not specified, a transformation to a usual contour file is assumed. In the former case, data from both both input files have to synchronized. This is done by specifying which columns contain data of the same variable in both files. Values from the position file are interpolated to those in the contour file, so that grid points do not need to match. This allows to use a contour file from adcpsect together with the output from getnav.

If no contour files are specified on the command line, standard input is assumed. Output is directed by default to standard output, unless an output file is specified with option -o. Input data must be separated by white spaces. Output data are written with format %15.6f and separated by a space. This utility can handle bad data which are defined with value 1.0E38.

Although this utility was created to manipulate files with contour data, it is supplied with many options and can in fact be used to perform other operations on file, such as filter out columns, changing the order of columns or inserting columns from another file.

## 3. OPTIONS

The following options are implemented:

-c column_list

  List of columns to read from the file specified with option -f. Data from these columns will be inserted in the same order as they appear in the list. See columns(5) for information on how to specify these columns. The default is 2,3 which corresponds to files generated by getnav.

-f file

  Specify the file containing additional position data. No default is supplied for this option. If not specified, a conversion to a usual and more simpler contour format will be carried out.

-i n

  Specify where in the input contour file data from the external file should be inserted. The value of n must correspond to a column number. All specified columns with option -c will be inserted, starting from this column number. Column numbering starts from one. Default is 2.

-o file

  Specify the file for new contour data. If not specified, standard output is assumed.

-x n

  Specify the column for synchronization of data. This the number of the column in the external file that contains data which appears also in the input contour file (see option -X). Column numbering starts from one. Default is 1.

-C column_list

  List of columns to read from the input control file. Data from these columns will be written in the same order as they appear in the list. See columns(5) for information on how to specify these columns. If a more generalized contour file is to be created, the default is 1,2,3. This allows to have input files with the following columns:

  1. Time in decimal days
  2. Bin depth
  3. Bin data
  If conversion to the usual contour format is required, the default is 1,4,5, which can be used for a file containing the following columns:
  1. Time in decimal days
  2. Longitude in decimal degrees
  3. Latitude in decimal degrees
  4. Bin depth
  5. Bin data
-X n

  Specify the column for synchronization of data. This the number of the column in the input contour file that contains data which appears also in the external file (see option -x). Column numbering starts from one. Default is 1

## 4. DEFAULT OPTIONS

If an external position file is specified, the default options allow a conversion to a more generalized contour format, where

- The input contour file has the following columns:
  1. Time
  2. Bin depth
  3. Bin data
  Such a file can be generated with xtract(1).
- The external file with additional position information correspond to the output of getnav.
- The output file has values of longitude and latitude inserted between time and bin depth data.
- Synchronization and interpolation of data is carried out on time data.

## 5. OUTPUT FILES

The file specified by the -o option.

## 6. EXAMPLES

Assuming getnav.nav is the file generated by getnav and adcpsect.con is the file generated by adcpsect, with the longitude as the x-axis for contours (found in the first column) and both U and V as bin data (found in the third and fourth columns, the second column containing bin depths). Then,

              con2con -f getnav.nav \
              -c '1,3' -x 2 -i 2    \
              -C '1,2,3,4' -X 1 adcpsect.con

will generate a more generalized contour file, inserting values of time and latitude (option -c) in the second aand third columns (option -i). All input columns from the contour file are kept (option -C). Synchronization of both files and interpolation of data from getnav.nav on the grid defined in adcpsect.con is carried out along longitude (options -x and -X.

In the example above, output is written to standard output. Piping it into a second call to con2con, such as

               con2con -C '2,1,3-6' -o output.con

will generate file output.con with columns containing longitude and time data swapped.

## 7. SEE ALSO

adcpsect,

columns(5),

con2db(1),

xtract(1),

## 8. NOTES

This is a Perl script, and could probably be more faster and handle numbers in a better way if coded in C.

## 9. AUTHOR

Pierre Jaccard, Geophysical Institute, University of Bergen, 1999

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