topic Re: Estimate area using geographic coordinates (Lat long) in SAS Programming

Estimate area using geographic coordinates (Lat long)

RandoDando — Wed, 29 Dec 2021 14:19:09 GMT

I have a data set which has sets of geographic coordinates for a list of properties. Each property has coordinates for buildings. How can I estimate the size of each property using these coordinates in SAS? I'm thinking I could go by the furthest points North, South, East, and West and use that to estimate the total area in acres (43,560 sq ft).

Re: Estimate area using geographic coordinates (Lat long)

RandoDando — Wed, 29 Dec 2021 14:24:09 GMT

As for precision, my data has Lat and Long at 6 decimal places.

Re: Estimate area using geographic coordinates (Lat long)

PaigeMiller — Wed, 29 Dec 2021 15:07:32 GMT

This is a situation where you have a very specific question, and the best way to get a solution is via Internet search.

"calculate area of polygon from lat long"

Here is a solution, it isn't SAS, but you could easily adapt it to SAS

https://www.sisense.com/blog/polygon-area-from-latitude-and-longitude-using-sql/

Re: Estimate area using geographic coordinates (Lat long)

RandoDando — Wed, 29 Dec 2021 15:11:27 GMT

Here is what I have, but the area values don't look correct. Am checking data...

proc sql;
create table MAX_COOR as select PROP, max(lat) as NORTH, min(lat) as SOUTH, max(lon) as EAST, min(lon) as WEST
from BLDGS 
group by PROP;
quit;

data dist; set MAX_COOR;
distance_length = geodist(NORTH, EAST, NORTH, WEST, 'M');
distance_width = geodist(NORTH, EAST, SOUTH, EAST, 'M');
run;

data area; set dist;
area_acres = (distance_length * distance_width)/640;
run;

Re: Estimate area using geographic coordinates (Lat long)

PaigeMiller — Wed, 29 Dec 2021 15:14:07 GMT

Share your data as SAS data step code (instructions)

Re: Estimate area using geographic coordinates (Lat long)

RandoDando — Wed, 29 Dec 2021 16:17:52 GMT

I figured out the issue. Elementary. To convert to acres I had to MULTIPLY the sq miles estimate by 640, not divide.

proc sql;
create table MAX_COOR as select PROP, max(lat) as NORTH, min(lat) as SOUTH, max(lon) as EAST, min(lon) as WEST
from BLDGS 
group by PROP;
quit;

data dist; set MAX_COOR;
distance_length = geodist(NORTH, EAST, NORTH, WEST, 'M');
distance_width = geodist(NORTH, EAST, SOUTH, EAST, 'M');
run;

data area; set dist;
area_acres = (distance_length * distance_width)*640;
run;