Same functionality and arguments as allocate_traces.
| Name | Format | Description |
| sepdata | sep_type | The name of the dataset. |
| fwind | integer array | Optional, first location along given access to |
| start allocating headers. | ||
| jwind | integer array | Optional, skip factor when allocating headers. |
| nwind | integer array | Optional, number of headers to allocate along |
| each axis. | ||
| tr_num | integer array (dim=1) | Optional, array which indicates whether or not |
| to allocate a given headers. |