In QGIS, I'm trying to create a new variable with a short description of a string value of another variable. For example, in the table below, I would like to have:
NAMEABB = "US 1" when NAME = "US Route 1";
NAMEABB = "I-5" when NAME = "Interstate Route 5";
NAMEABB = "SR 539" when NAME = "State Route 539".
I've tried extracting the numbers with regular expressions (building upon this post), but I get always NULL. Any hints?
The addition of multiple routes in one line slightly complicates the calculation because the routes will have to be broken up, renamed with abbreviations, and then reassembled back into one line.
When working with more than just a couple of conditions, I prefer to use either 13.2.16.3 map - List of functions - QGIS Documentation or 13.2.4.1 CASE - List of functions - QGIS Documentation instead of large if blocks.
array_to_string(
array_foreach(
string_to_array("NAME", ','),
with_variable(
'rename',
map(
'Interstate Route ', 'I-',
'US Route ', 'US ',
'Alternate US Route ', 'Alt US ',
'State Route ', 'SR '
),
with_variable(
'name',
regexp_substr(
@element,
'^\\p{Z}*([\\p{L}|\\p{Z}]+)\\p{N}+'
),
replace(
@element,
@name,
map_get(@rename, @name)
)
)
)
),
','
)
You can use regexp_match to select feature records that contain specific strings and then regexp_replace to change those strings. In QGIS Field Calculator, run this script:
if(regexp_match("NAME",'US Route'),regexp_replace("NAME",'US Route','US'),
if(regexp_match("NAME",'Interstate Route '),regexp_replace("NAME",'Interstate Route ','I-'),
if(regexp_match("NAME",'State Route'),regexp_replace("NAME",'State Route','SR'),
"NAME")))
You can add more nested if statements for any other text you want to replace, just make sure to add additional ending parentheses at the end of the script.
This is the output from the above script:
if(regexp_match("NAMEABB",', State Route'),regexp_replace("NAMEABB",', State Route',', SR'),"NAMEABB")