How to use the command fdp (with examples)

The fdp command is a part of the graphviz package, and it is used to render an image of a force-directed network graph from a graphviz file. It supports various layouts such as dot, neato, twopi, circo, fdp, sfdp, osage, and patchwork. The fdp command provides several options to generate network graphs in different output formats like png, svg, ps, pdf, fig, gif, jpg, json, and dot.

Use case 1: Render a png image with a filename based on the input filename and output format (uppercase -O):

Code:

fdp -T png -O path/to/input.gv

Motivation: This use case is useful when you want to generate a png image of a network graph from a graphviz file, and the output filename is based on the input filename.

Explanation:

• fdp: The command to render the image.
• -T png: Specifies the output format as png.
• -O path/to/input.gv: Sets the output file name based on the input file name.

Example output: The fdp command will generate a png image of the network graph based on the input.gv file and save it as path/to/input.png.

Use case 2: Render a svg image with the specified output filename (lowercase -o):

Code:

fdp -T svg -o path/to/image.svg path/to/input.gv

Motivation: This use case is useful when you want to generate an svg image of a network graph from a graphviz file and specify a custom output filename.

Explanation:

• fdp: The command to render the image.
• -T svg: Specifies the output format as svg.
• -o path/to/image.svg: Sets the output file name as path/to/image.svg.
• path/to/input.gv: The input file name.

Example output: The fdp command will generate an svg image of the network graph based on the input.gv file and save it as path/to/image.svg.

Use case 3: Render the output in a specific format:

Code:

fdp -T ps|pdf|svg|fig|png|gif|jpg|json|dot -O path/to/input.gv

Motivation: This use case is useful when you want to render the output network graph in a specific format other than the default png or svg formats.

Explanation:

• fdp: The command to render the image.
• -T: Specifies the output format. It can be one of the following: ps, pdf, svg, fig, png, gif, jpg, json, or dot.
• -O path/to/input.gv: Sets the output file name based on the input file name.

Example output: The fdp command will generate an image of the network graph based on the input.gv file and save it in the specified format (e.g., ps, pdf, svg, etc.).

Use case 4: Render a gif image using stdin and stdout:

Code:

echo "digraph {this -> that} " | fdp -T gif > path/to/image.gif

Motivation: This use case is useful when you want to generate a gif image of a network graph from the stdin input and save it with a custom filename.

Explanation:

• echo "digraph {this -> that} ": Provides the dot representation of the network graph as input using stdin.
• |: The pipe symbol is used to redirect the output of the echo command to the fdp command.
• fdp -T gif: Specifies that the output format should be gif.
• > path/to/image.gif: Redirects the output of the fdp command to the file path/to/image.gif

Example output: The fdp command will generate a gif image of the network graph provided in the stdin (in this case, a simple graph with a single edge) and save it as path/to/image.gif.

Use case 5: Display help:

Code:

fdp -?

Motivation: This use case is useful when you want to view the help information and usage examples of the fdp command.

Explanation:

• fdp: The command to render the image.
• -?: Displays the help information for the fdp command.

Example output: The fdp command will display the help text, which includes usage examples and additional information about the fdp command.