- -i label1 -i label2 ... -o outputlabel
This is a simple script that will merge two or more label files. It does this by catting the label files together (after removing the first two lines). It inserts a new header (the first two lines). The number of entries in the new file (ie, the number on the second line), is computed by summing those from the input files.
Label file format
Labels are simple text files. The first line is a header. Each following line contains data with 5 columns. The first column is the vertex number of the label point. The next 3 columns are the X, Y, and Z of the point. The last can be ignored. If the label is not a surface-based label, then the vertex number will be -1.