---
name: "r.transect"
section: "1grass"
platform: "linux"
package: "grass-doc"
version: "8.4.1-1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/r.transect"
---

# r.transect(1grass)

Outputs raster map layer values lying along user defined transect line(s).

## NAME

**r.transect**  - Outputs raster map layer values lying along user defined transect line(s).

## KEYWORDS

raster, profile, transect

## SYNOPSIS

**r.transect**\
 **r.transect --help**\
 **r.transect** \[-**g**\] **map**=*name* **line**=*east,north,azimuth,distance*\[,*east,north,azimuth,distance*,...\]  \[**null\_value**=*string*\]   \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-g**

  Output easting and northing in first two columns of four column output

- **--help**

  Print usage summary

- **--verbose**

  Verbose module output

- **--quiet**

  Quiet module output

- **--ui**

  Force launching GUI dialog

### Parameters:

- **map**=*name* **\[required\]**

  Raster map to be queried

- **line**=*east,north,azimuth,distance\[,east,north,azimuth,distance*,...\] **\[required\]**

  Transect definition

- **null\_value**=*string*

  String representing NULL value\
   Default: *\**

## DESCRIPTION

*r.transect* outputs, in ASCII, the values in a raster map which lie along one or more user-defined transect lines. The transects are described by their starting coordinates, azimuth, and distance.

The **line** parameter is a definition of (each) transect line, specified by the geographic coordinates of its starting point (*easting,* *northing*), the angle and direction of its travel (*azimuth*), and its distance (*distance*).

The *azimuth* is an angle, in degrees, measured to the east of north.  The *distance* is in map units (meters for a metered database, like UTM).

The **null** parameter can optionally be set to change the character string representing null values.

## NOTES

This program is a front-end to the  *r.profile* program.  It simply converts the azimuth and distance to an ending coordinate and then runs  *r.profile*. There once were **width=** and **result=***raw\|median\|average* options which are not currently implemented.

## SEE ALSO

*r.profile,* *wxGUI profile tool*

## AUTHOR

Michael Shapiro, U.S. Army Construction Engineering Research Laboratory

## SOURCE CODE

Available at: r.transect source code (history)

Accessed: Monday Feb 24 17:50:55 2025

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