Whilst I am waiting for the book to arrive I have started playing a bit with the sample dataset of North Carolina. I am interested in the streets layer (dataset) since basiclaly I am about to do some routing work.
Can someone please be kind enough to explain to me what do these columns represent?
-> ncexternal/: NC original data set sources, metadata and copies of some
original data
-> take metadata link
-> Streets.shp ... streets_wake_legend.csv
Most columns are explained there (as I could reconstruct them from the
original metadata
which you also find linked there (see "Data URL")).
Hope this helps,
Markus
Yancho wrote:
Hi,
Whilst I am waiting for the book to arrive I have started playing a bit
with
the sample dataset of North Carolina. I am interested in the streets layer
(dataset) since basiclaly I am about to do some routing work.
Can someone please be kind enough to explain to me what do these columns
represent?
May I ask some more questions please to better understand the dataset?
FT_COST;Enhance Routing - Travel time in minutes ← does this mean the time in minutes taken from Target Id to Source Id depending on the “speed” column?
TF_COST is Source ID to Target Id right?
And taking the lenght as the cost of going through that node in a routing network, am I right in the following conclusions :
I can make another column length with the value of length(the_geom)
If street is BI-directional, thus one_way = “BI”, that means that cost = length and reverse_cost = length
If street is TF directional, thus one_way = “TF” that means that cost = length and reverse_cost = 1000 + length (made 1000 as a big number so for sure it is not included in the routing)
If street is FT directional, thus one_way = “FT” that means that cost = length + 1000 and reverse_cost = length
Now on the dataset is 1000 a huge number? Should I reduce it to a smaller number / increase it to a bigger number / make it negative?
For my routing I am using pgRouting.
Thanks alot for the time you are investing in GRASS
you can find the legend here: http://www.grassbook.org/data_menu3rd.php
→ ncexternal/: NC original data set sources, metadata and copies of some
original data
→ take metadata link
→ Streets.shp … streets_wake_legend.csv
Most columns are explained there (as I could reconstruct them from the
original metadata
which you also find linked there (see “Data URL”)).
Hope this helps,
Markus
Yancho wrote:
Hi,
Whilst I am waiting for the book to arrive I have started playing a bit
with
the sample dataset of North Carolina. I am interested in the streets layer
(dataset) since basiclaly I am about to do some routing work.
Can someone please be kind enough to explain to me what do these columns
represent?
