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

# v.in.mapgen(1grass)

Imports Mapgen or Matlab-ASCII vector maps into GRASS.

## NAME

**v.in.mapgen**  - Imports Mapgen or Matlab-ASCII vector maps into GRASS.

## KEYWORDS

vector, import

## SYNOPSIS

**v.in.mapgen**\
 **v.in.mapgen --help**\
 **v.in.mapgen** \[-**fz**\] **input**=*name*  \[**output**=*name*\]   \[--**overwrite**\]  \[--**help**\]  \[--**verbose**\]  \[--**quiet**\]  \[--**ui**\]

### Flags:

- **-f**

  Input map is in Matlab format

- **-z**

  Create a 3D vector points map from 3 column Matlab data

- **--overwrite**

  Allow output files to overwrite existing files

- **--help**

  Print usage summary

- **--verbose**

  Verbose module output

- **--quiet**

  Quiet module output

- **--ui**

  Force launching GUI dialog

### Parameters:

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

  Name of input file in Mapgen/Matlab format

- **output**=*name*

  Name for output vector map (omit for display to stdout)

## DESCRIPTION

*v.in.mapgen* allows the user to import Mapgen or Matlab vector maps into GRASS.

## NOTES

This module only imports data into vector lines.

The user can get coastline data in Mapgen or Matlab format from NOAA’s Coastline Extractor at https://www.ngdc.noaa.gov/mgg/shorelines/shorelines.html.

Matlab vector line maps are simply a series of "x y" data points. Lines are separated by a row containing `NaN NaN`. Output from Matlab with this command:\
\

```
    save filename.txt arrayname -ASCII
```

The user can import 3D lines from Matlab by exporting a 3 column array and using the **-z** flag.

## SEE ALSO

*v.in.ascii*

## AUTHORS

Based on *v.in.mapgen.sh* for GRASS 5.0 by Andreas Lange\
 Rewritten for GRASS 6 by Hamish Bowman

## SOURCE CODE

Available at: v.in.mapgen source code (history)

Accessed: Monday Feb 24 17:51:46 2025

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