# PostGIS Cartographic Effects– Cartoonify Nearly Coincident Lines

In my previous post, a long 24-hours ago, I proposed some automatic modification of line for cartographic reasons. I had some flaws in my code. The points were over-rotated by 45 degrees. Can you spot why? Tip: it’s a basic trigonometric mistake. Here’s the corrected code (though there may be a better way):

```CREATE TABLE movedRoad AS
SELECT
ST_Translate(b.the_geom,
0.5 * ST_Distance(b.the_geom, ST_Union(a.the_geom)) * (cos(ST_Azimuth(b.the_geom, ST_ClosestPoint(ST_Union(a.the_geom), b.the_geom))) - 3.14159/4),
0.5 * ST_Distance(b.the_geom, ST_Union(a.the_geom)) * (sin(ST_Azimuth(b.the_geom, ST_ClosestPoint(ST_Union(a.the_geom), b.the_geom))) - 3.14159/4) )
AS the_geom
GROUP BY a.id, b.the_geom
;
```

An alternate approach is to only move those points that are too close, ala:

```CREATE TABLE movedRoadAgain AS
SELECT
ST_Translate(b.the_geom,
(100 - ST_Distance(b.the_geom, ST_Union(a.the_geom))) * (cos(ST_Azimuth(b.the_geom, ST_ClosestPoint(ST_Union(a.the_geom), b.the_geom))) - 3.14159/4) ,
(100 - ST_Distance(b.the_geom, ST_Union(a.the_geom)))* (sin(ST_Azimuth(b.the_geom, ST_ClosestPoint(ST_Union(a.the_geom), b.the_geom))) - 3.14159/4) ) AS the_geom
GROUP BY a.id, b.the_geom
HAVING ST_Distance(b.the_geom, ST_Union(a.the_geom)) < 100

UNION ALL

SELECT
b.the_geom AS the_geom
FROM bridle_points b, apt a
GROUP BY a.id, b.the_geom
HAVING ST_Distance(b.the_geom, ST_Union(a.the_geom)) >= 100
;
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