Here's what I'd do. Without looking at your workbook, or the data:
First, grab a SHP of USA (Admin 0) or OSM "Coastlines" from cloudmade "United States". You'd need to edit Admin 0. Whichever, you'll need to do ESRI -> ET Wizards Polyline to Point. That will give you an X, Y for both Pacific and Atlantic Coastline, plus the Gulf.
Then, you'll need the centroids of Tiger ZCTA file, to get this you would do ESRI -> polygon to points, centroids only.
You then export the data table(s) (If merged SHP then this is singular) to CSV. Create a column in each CSV, and fill the relevant one with "Coast" or "Zip". Append the CSVs. (Optional) Pre-process min distance formula in CSV, or create a Calculated Field in Tableau - your choice, personally, I'd be making another distance table, and bringing that in.
I realize this post is a few years old, but does anyone know if a template file exists from above method with coordinates of USA coastline? I've search the KB but could not find anything beyond the coordinates for a few midwest state boundaries.
Hi John - Did you ever find a database with USA coastline coordinates?
Hi Rose, Good to hear from you! Hope all is well. I never did get anything good on this. I did find something online but it was not very granular and thus not useful. The coast line (especially east coast) is so irregular with all the barrier islands, coves, etc.
Downloaded Coastline from Natural Earth Data
Downloaded ZCTA from USGS Tiger
QGIS: Find nodes from Coastline (i.e Points)
Find centroids from ZCTA (i.e. Points)
NNJoin ZCTA to Coastline
Save as CSV
ZCTA on LOD Dual Axis filled map & Point
Filled Map Color Distance
Circle Color Distance Size Distance
Zip to Coastline.twbx 2.1 MB