To do this, use either get_mat (for Matlab format data) or getLR for older LDR format data (mainland systems, pre 2000).

get_mat

The get_mat command has the following syntax:

get_mat {target directory} < {catalogue file}

The catalogue file is the file containing the catalogue listing created using the TAPECAT command (see Section 5). The target directory can be an absolute or relative pathname, and is the directory into which the raw data will be written. The target directory should not exist at the time the command is given, as it will be created at runtime.

The target directory should be a sub-directory of one of the temporary storage areas, such as /stager/y.

Ideally a sub-directory of the stager area should be created which identifies the owner of the data, and the target directory should then be a sub-directory of that, i.e.

/stager/y/ian/jun1796_tro_raw

getLR

The syntax for getLR is as follows:

getLR < {catalogue file} > {LDR file}

The LDR file can be a filename with either a full or a relative pathname.

As with get_mat, the catalogue file is the file containing the catalogue listing created using the TAPECAT command. The ldr file is a (large) file containing the data in LDR format. Because of their large size, LDR-format files should only ever be written to the /stager areas. An even better option, however, is not to write the LDR file at all, but to send the LDR-format data into another program for conversion into integrated data format or matlab format, via a unix pipe. Section 7 describes how to do this.

The getLR and get_mat programs first check whether any of the requested data already exists on one of the stager areas. If so, then in get_mat soft links to the existing files are created in the target directory. In getLR, the data already present on the disk are used to create the ldr file. If the data do not already exist, then a request is made to the central on-line data store at RAL, asking for the relevant data tape to be mounted. This can take some time, depending on the number and volume of requests that have been sent to the tape store by other users.

Data are always staged in over the network to the top level of one of the stager areas. In get_mat, soft links are then created from the target directory to these files. Note that the target directory specified in get_mat will only ever contain soft links, and never the files themselves, though the difference should be indistinguishable to most users.

In cases where the get_mat command has been used to stage in matlab format files, the soft links will appear in the data directory together with a file called filelist.dat, which summarises the contents of the directory (one file per line). This listing is needed by the subsequent matlab programs that will read the data, so don't delete it!