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[](http://travis-ci.org/diagrams/diagrams-svg)
_diagrams-svg_ is a an SVG backend for [diagrams]. Diagrams is a powerful,
flexible, declarative domain-specific language for creating vector graphics,
using the [Haskell programming language][haskell].
[diagrams]: http://projects.haskell.org/diagrams/
[haskell]: http://www.haskell.org/haskellwiki/Haskell
_diagrams-svg_ is the default out-of-the box backend that comes with
the diagrams framework, and supports most features defined in [diagrams-lib].
[diagrams-lib]: http://hackage.haskell.org/package/diagrams%2Dlib
# Installation
```
cabal update && cabal install diagrams-svg
```
# Usage
A simple example that uses _diagrams-svg_ to draw a square.
```haskell
import Diagrams.Prelude
import Diagrams.Backend.SVG.CmdLine
b1 = square 20 # lw 0.002
main = mainWith (pad 1.1 b1)
```
Save this to file named `Square.hs` and compile this program:
```
ghc --make Square.hs
```
This will generate an executable which, when run produces an SVG file. Run the
executable with the `--help` option to find out more about how to call it.
```
$ ./Square --help
./Square
Usage: ./Square [-w|--width WIDTH] [-h|--height HEIGHT] [-o|--output OUTPUT] [--loop] [-s|--src ARG] [-i|--interval INTERVAL]
Command-line diagram generation.
Available options:
-?,--help Show this help text
-w,--width WIDTH Desired WIDTH of the output image
-h,--height HEIGHT Desired HEIGHT of the output image
-o,--output OUTPUT OUTPUT file
-l,--loop Run in a self-recompiling loop
-s,--src ARG Source file to watch
-i,--interval INTERVAL When running in a loop, check for changes every INTERVAL seconds.
```
You _must_ pass an output file name with a `.svg` extension to generate the SVG
file.
```
$ ./Square -o square.svg
```
The command above generates the SVG file:
```
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN"
"http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" version="1.1" width="22.0" height="22.0" viewBox="0 0 22 22">
<g>
<g stroke="rgb(0,0,0)" stroke-opacity="1.0" fill="rgb(0,0,0)" fill-opacity="0.0" stroke-width="2.0e-3">
<path d="M 21.0,21.0 l -2.220446049250313e-15,-20.0 h -20.0 l -2.220446049250313e-15,20.0 Z" />
</g>
</g>
</svg>
```
|
