NASA-Ames file format - Commonly met problems

This page describes some common mistakes made when constructing NASA-Ames files.

Use of commas to separate data values. Data values should be separated by one or more spaces.
Blank lines appearing within the data section of the file, particularly at the end of the file. Blank lines appearing in the data section of the file will produce the following message from the format checking program:
**PARDAT error--no numbers in line <Line no. >
Use of non-numeric characters in data for File Format Index (FFI) 1001 files. The data items for FFI 1001 should consist of real numbers only (the characters "+", "-", "e" or "E" are also allowed). Any non-numeric character, including the character "/" used as part of a date, is invalid and will be reported as an error.
Incorrect use of "fractional julian day" as independent variable. The fractional julian day should be a real number. This is generated by adding the day number - day 1 is January 1st - to the fractional day, which should normally be expressed to an accuracy of six figures. For example, 2.525706 translates to 12:37:01 on 2nd January.
When using FFI 1001 the independent variable must be monotonic (ie should be increasing or decreasing for each row, but not remaining the same or changing direction). If you are using the fractional julian day, and have entered it correctly, then this will be automatically the case. The format checking program will reject FFI 1001 files where the independent variable is not monotonic.
Specifying a "missing data" value for a parameter which is smaller than the largest valid data value.
Specifying the wrong number of header lines. The first number of the first record of the file should contain the number of header lines in the file. This value should include all lines in the file up to the first data record. It includes the first line of the file, containing the number of header lines and the File Format Index.
The number of columns of data do not match the number of parameters specified in the header.
Use of tab characters. Tabs should not be used in NASA-Ames files. The format checking program will report any tabs found with the message
**Found non-printable character with ASCII decimal value = 9
For simplicity, the file uploader and format checking programs replace tab characters with spaces automatically before processing your file, so you should not normally see this message. Note that this may alter the visual appearance of you files so, if possible, please do not generate files containing tabs.