placemat prints out a pairwise distance matrix between placements.
usage: placemat [options] placefile
| -o | Specify the filename to write to. |
| --out-dir | Specify the directory to write files to. |
| --prefix | Specify a string to be prepended to filenames. |
| --csv | Output the results as csv instead of a padded matrix. |
| --point-mass | Treat every pquery as a point mass concentrated on the highest-weight placement. |
| --pp | Use posterior probability for the weight. |