- What kind of text files?
- What is an ASCII File?
- How do I know I have an ASCII file?
- What is the difference between DOS ASCII and UNIX ASCII?
- What are Column and Character delimited files?
- What kind of files aren't ASCII?
- What data formats does the program accept?
What kind of data will Coordinate Data Conversion convert?
Coordinate Data Conversion will convert coordinate data from either of two data sources. CDC will read column and character-delimited DOS ASCII files. CDC can also use ODBC drivers to attach to any ODBC-compatible database; reading from, and writing directly to, the database fields.
An ASCII file is the most simple/common data-file type. Its opposite is a binary file. ASCII files are also commonly referred to as plain text files. Most programs that import and export data, and nearly all mapping programs, can read/write or import/export ASCII files.
How do I know I have an ASCII file?
A good test is to try to read your data with a plain text editor. Two good plain text editors come with Windows, Notepad and Wordpad. To test your file, do the following steps:
Click on the Start Button.
Select Programs => Accessories => Notepad from your Start Menu.
From the Notepad main menu, select File => Open, and select your data file. Notepad has a file-size limit. If your file is too large for Notepad, you will be given the option of using Wordpad instead. Go ahead and do so.
If you can read the data in your file in Notepad/ Wordpad, if it looks normal with no funny characters, then you have an ASCII file. If you can't, then you have a binary file.
What is the difference between DOS ASCII and UNIX ASCII?
When the first PC operating system (CPM) was created, they made two major mistakes (IMHO). The first mistake was flipping the path symbol around from the UNIX standard of '/' to the DOS standard of '\'. This is a major pain to those of us who live in both the DOS and UNIX worlds ( I have seen a written apology from the guy who takes the blame for this mistake). The second mistake was in choosing which characters denote a new line in a text file. In both UNIX and DOS, there are non-printing ASCII characters at the end of each line, that tell a text display program that the following text should be displayed on a new line. UNIX uses the Linefeed character (ASCII character 10) to denote the end of a line. DOS uses the Carriage Return followed by the Linefeed character (ASCII character 13 & ASCII character 10) to denote a new line. As a consequence, UNIX text files won't display properly in most DOS/Windows text editors, and DOS text files don't display properly in UNIX text editors. There are ways to get around this problem, the simplest is to use ASCII FTP to convert between the two file formats. The Coordinate Data Conversion program does not properly handle UNIX style ASCII files. Any UNIX ASCII file must be converted to a DOS ASCII file before it can be processed with Coordinate Data Conversion
What are Column and Character-delimited files?
In a column-delimited file, the data values line up vertically from line to line in the input data file. If latitude (or longitude, or X, or Y) is in columns 24 to 32 in the first line, it must also be in columns 24 to 32 in all following lines. Most ASCII data files are column-delimited. It is important to note, that not all data files that appear to be column-delimited, are column-delimited. If tabs have been used to line up data in an ASCII file, then the program is not column delimited, as each line will not have the same number of characters.
Not all ASCII data files are column-delimited. Some are character-delimited. In character-delimited data files, the data don't line up vertically. Instead, there is some character that separates the different data fields in each record. Often this is a comma (,), a semicolon(;), a quote ('), a tab or a space. In a character-delimited file, data won't always line-up vertically from record to record, but it will line up logically. If latitude (or longitude, or X, or Y) is in the third field in the first line, it must also be in the third field in all following lines. Coordinate Data Conversion will read either column or character-delimited data files.
What kind of files aren't ASCII?
Generally, any program that uses a proprietary file format, uses a binary file. Binary files are smaller, and therefor quicker than ASCII files, but they are also generally unique to the program that created them. Examples of binary files are spreadsheet files such as Excel's *.xls files, database files such as Access's *.mdb files or CAD program files such as AutoCAD's *.dxf and *.dwg files. Coordinate Data Conversion cannot read binary files. Fortunately, nearly all major programs that use binary files also provide a means of creating an ASCII file output.
Open DataBase Connectivity (ODBC) is a standard that allows for (relatively) easy access to data stored in databases. The ODBC standard allows users and user programs to access data stored in proprietary database formats, such as Oracle or Microsoft Access, through a common interface. This access happens through a set of utilities called 'ODBC drivers'. These drivers are generally written and supplied by the authors of the proprietary database programs, and are usually installed on a client PC when the database software is installed on the machine. Microsoft Windows comes with several of these drivers pre-installed, specifically those for Microsoft proprietary databases Access and FoxPro, along with two less-obvious drivers, one for Excel and one for 'Text Files'. Personally, I've never tried to use the 'Text Files' ODBC drivers, as I've never seen a good reason to do so. The instructions for using the Excel ODBC drivers are in the Excel Help Files. I've tried to use these once, with less than stellar success. I found the instructions to be less than readable.
To find a list of ODBC drivers loaded on your machine, run the ODBC Data Sources applet found in the Control Panel of Win95/98/ME and NT 4.0 or under the Administrative Tools applet found in the Control Panel of NT2K.
How do I convert data in a spreadsheet?
If your spreadsheet has ODBC drivers, and you're feeling particularly lucky, try defining an ODBC data source for your spreadsheet. Otherwise, one would probably be best off saving the spreadsheet as a tab- delimited file. For Excel, the steps are:
Select Save as… from the File option of the Main Menu of Excel. This will bring up the Save As dialog box.
Go to the bottom of the Save As dialog box to the Save as type drop-down list box. Click on the down arrow on the right-hand edge of the drop-down list box and select the Text (Tab Delimited) (*.txt) option from this list.
Use the Save As dialog box to select the directory that you want to contain your data file.
Use the Save As dialog box to give your data file the desired name (note: Excel will automatically append the .txt suffix to the name you select).
Click on the Save button.
What data formats does the program accept in text files?
Just about anything. The program was written to be extremely flexible. If the data are in column-delimited form, the program will read virtually any lat/long format. If the data are in a character-delimited format, the program is less flexible. In character-delimited files, lat/long data can be in either decimal degree (dd) or degree - minute - second (dms) format. In either format, dd, or dms, the degree value must be separated from the decimal or minute - seconds portion of the value by a decimal point (e.g. 22 degrees - 16 minutes - 42.76 seconds will/must be displayed as 22.164276). Input lat/long data can either be signed, letter denoted, or forced. In signed data, positive latitudes are in the Northern Hemisphere, negative latitudes in the Southern Hemisphere, positive longitudes are east of the projection Prime Meridian (usually Greenwich) and negative longitudes are west of the projection Prime Meridian. In letter-denoted format, hemispheres are specified by the letters 'N/S/E/W' or 'n,s,e,w'. In forced data, any sign information is ignored, and the hemisphere is user selected.
What data formats does the program accept in ODBC data sources?
The program will read from, and write to, fields in an ODBC- compliant database, if and only if, those fields are a numeric type. The program will not read or write data in a text field. Lat/long data can be in either decimal degree (dd) or degree - minute - second (dms) format. In either format, dd, or dms, the degree value must be separated from the decimal or minute - seconds portion of the value by a decimal point (e.g. 22 degrees - 16 minutes - 42.76 seconds will/must be displayed as 22.164276). Input lat/long data can either be signed, or forced. In signed data, positive latitudes are in the Northern Hemisphere, negative latitudes in the Southern Hemisphere, positive longitudes are east of the projection Prime Meridian (usually Greenwich) and negative longitudes are west of the projection Prime Meridian. In forced data, any sign information is ignored, and the hemisphere is user selected.
What updates are available for the software?
If one is running a version of Coordinate Transform that is older than 3.1, it is strongly recommended that it be updated to version 3.1. If one is running CDC. or Coordinate Transform v3.1, the following updates are available:
To update, download the file and double-click on it. When the dialog box appears asking if it's OK to modify the Registry, click on the OK button.