They don’t actually exist. Part of the script that generates the manual pages runs this map, but fills in random data. However, a standard Cacti network traffic rrd file (which is what it works with by default), looks something like this:
filename = "switch_traffic_in_22.rrd"
rrd_version = "0003"
step = 300
last_update = 1497011702
header_size = 5216
ds[traffic_in].index = 0
ds[traffic_in].type = "COUNTER"
ds[traffic_in].minimal_heartbeat = 600
ds[traffic_in].min = 0.0000000000e+00
ds[traffic_in].max = 1.0000000000e+13
ds[traffic_in].last_ds = "0"
ds[traffic_in].value = 0.0000000000e+00
ds[traffic_in].unknown_sec = 0
ds[traffic_out].index = 1
ds[traffic_out].type = "COUNTER"
ds[traffic_out].minimal_heartbeat = 600
ds[traffic_out].min = 0.0000000000e+00
ds[traffic_out].max = 1.0000000000e+13
ds[traffic_out].last_ds = "0"
ds[traffic_out].value = 0.0000000000e+00
ds[traffic_out].unknown_sec = 0
which (according to this tool), comes from:
rrdtool create switch_traffic_in_22.rrd --start 1497012302 --step 300 \
All weathermap actually cares about is the ds names. You can specify them in the
TARGET though, and use any rrd file you already have.