cd_air

• purpose
• usage
• examples
• comments
• see also

Purpose:

This program will change the directory of the reslice target in the designated .air file while leaving the actual file name unchanged. This utility is designed to allow you easily update .air files in the event that you choose to move your original data to some new directory.

Usage:

cd_air .air-file new-directory [foreign-path-separator ]

where the following definitions apply:

.air-file

the name of the .air file

new-directory

the name of the directory that now contains the reslice file specified in the .air file. (scanair can be used to identify the name of the reslice file specified in a given .air file).

foreign-path-separator

the path separator used to separate directories from files on a foreign computer platform that uses a different separator from the local platform. For example, PC's use a backslash '\' whereas Unix systems use a forward slash '/' to separate directories and files. Thus when moving .air files from a PC to a UNIX system, a foreign path separator of '\' must be specified. As an additional complication, backslashes are escape characters on UNIX systems, so a double backslash must be used '\\' so that the first backslash escapes the second.

Examples:

• The reslice file in mri.air will now target the same file name as it did before, but the directory in which the file is presumed located is changed to /data/experiment1/
• This example is UNIX specific, since it uses UNIX style paths

Comments:

• The standard file is not updated, so if you subsequently use invert_air, you will need to use this program again on the inverted .air file (assuming that the standard file was moved as well).
• As a safety measure, the name of the old reslice directory is stored in the .air file comment line where it can be accessed using scanair. Note that a second application of this program will lose the original reslice directory completely.
• Move the reslice file before you update the .air file if possible. This will allow the program to verify the dimensions and sizes of the reslice file and warn you if the file in the directory that you have designated has the same name but is not compatible.
• If compiled to allow automatic detection and application of byte swapping, AIR can use .air files from bigendian or littleendian machines interchangeably so long as both platforms conform to the IEEE Standard for Binary Floating-Point Arithmetic (ISO/IEEE Std 754-1985) and represent relevant variables with the same total number of bytes. The foreign-path-separator optional argument further supports cross platform migration of .air files

See also:

• cd_warp
• mv_air