# Calculating distance to a feature from a reference line

I have multiple shapefiles, each containing a coastline for a specific year. I want to calculate the perpendicular distance to the shoreline from a fixed vertical reference line.

Please recommend me the best tool (in ArcGIS-Desktop) to find out the perpendicular distance from each point (or a definite number of multiple points) on the reference line to the shoreline shapefile. I have included a screenshot to describe what I am planning to achieve.

I am hoping to be able to create 1 custom point per 100m on the reference line and then calculate the distance to the shoreline from these points.

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This is two different questions, although you might not have intended it. The diagram shows a computation of the distance from a point to a line. Your last paragraph asks to compute distances from points on the line back to a feature. Those will not be the same! Which of these two operations do you actually want? – whuber Jul 30 '13 at 14:01

## 2 Answers

Near tool determines the distance from each feature in the input features to the nearest feature in the near features, within the search radius.

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Yes, I did check the Near tool. But, unfortunately, I think it does not solve my problem as I am interested in determining the distance in a particular direction (see figure) and not just the nearest feature (as given by the Near tool). – Aditya Jun 30 '13 at 9:23

Does the vertical line always have the same X value within the projection you are using?

If so you can find the distance by calculating the difference between the X value of the vertical line, and the X value of the point.

The following field calculator python snippet would calculate this:

``````abs(!SHAPE.CENTROID.X! - 50000)
``````

This assumes that your vertical line has an X value of 50,000.

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