gratools stats๏ƒ

Comprehensive statistics for pangenome graph size, connectivity, and complexity.

๐Ÿ“ˆ Graph Insights

The stats command parses the GFA file (or uses the GraTools index) to calculate essential metrics. It provides a high-level understanding of the graphโ€™s properties, which is crucial for quality control and structural analysis of the pangenome.

Options๏ƒ

๐Ÿ› ๏ธ View Command Line Options
$ gratools stats
Welcome to GraTools version: '1.1.0.dev7'
@author: GraTools team's
        ____                 __________               ____          
      6MMMMMb/               MMMMMMMMMM               `MM          
     8P    YM               /   MM     \               MM          
    6M      Y ___  __    ___    MM   _____     _____   MM   ____   
    MM        `MM 6MM  6MMMMb   MM  6MMMMMb   6MMMMMb  MM  6MMMMb\ 
    MM         MM69 " 8M'  `Mb  MM 6M'   `Mb 6M'   `Mb MM MM'    ` 
    MM     ___ MM'        ,oMM  MM MM     MM MM     MM MM YM.      
    MM     `M' MM     ,6MM9'MM  MM MM     MM MM     MM MM  YMMMMb  
    YM      M  MM     MM'   MM  MM MM     MM MM     MM MM      `Mb 
     8b    d9  MM     MM.  ,MM  MM YM.   ,M9 YM.   ,M9 MM L    ,MM 
      YMMMMM9  _MM_   `YMMM9'Yb_MM_ YMMMMM9   YMMMMM9 _MM_MYMMMM9 
        \                                    /                /
        /''A''\          /''''''\           /     /''''A'''''\
  ...GC|       |..ATG...C...CG...T....TAG..'..GC.|            |...
        \..C../      \.............../            \...TATA.../
 
Please cite our gitlab: https://forge.ird.fr/diade/gratools.git\

Usage: gratools stats [OPTIONS]

  Parses a GFA file (or uses an existing GraTools index) to compute various
  statistics about its structure, including segment counts, link properties,
  walk characteristics, and connectivity. Results are displayed in the terminal
  and saved to a file within the GraTools index directory.
  
  For more details, see the full documentation:
  https://gratools.readthedocs.io/en/latest/commands/stats.html

Statistics Options:
  -g, --gfa PATH
     Path to the input GFA file (e.g., myGraph.gfa or myGraph.gfa.gz).
     [required]

  -o, --outdir DIRECTORY
     Output directory for GraTools results. If not specified, results are
     typically placed in a subdirectory within the GFA file's parent directory
     (e.g., 'GraTools-output_<gfa_name>').

  --by-category / --single-table
     Display statistics in separate tables per category instead of one
     consolidated table.  [default: single-table]

  --save / --no-save
     Save the statistique to a CSV file.  [default: no-save]

Logging Options:
  -vv, --verbosity [DEBUG|INFO|ERROR]
     Set the logging verbosity level.  [default: INFO]

  -l, --log-path DIRECTORY
     Directory where the log files will be saved. If not specified, logs will be
     placed in the main output directory (or in a default GraTools log
     location).

Performance Options:
  -t, --threads INTEGER
     Number of threads to be used for parallelizable operations.  [default: 1]

Other options:
  -h, --help
     Show this message and exit.

Usage Examples๏ƒ

1. Consolidated Statistics (Default)

Calculates all statistics and displays them in a single, comprehensive table.

$ gratools stats -g Og_cactus.gfa.gz
 โ•ญโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฎ
 โ”‚ Category                โ”‚ Metric                                                      โ”‚ Value                                                                โ”‚
 โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ค
 โ”‚ Graph Overview          โ”‚ GFA File Name                                               โ”‚ Og_cactus                                                            โ”‚
 โ”‚ Graph Overview          โ”‚ GFA Version                                                 โ”‚ 1.1                                                                  โ”‚
 โ”‚ Graph Overview          โ”‚ Total Segments (S lines)                                    โ”‚ 2,354,995                                                            โ”‚
 โ”‚ Graph Overview          โ”‚ Total Links (L lines)                                       โ”‚ 6,670,282                                                            โ”‚
 โ”‚ Graph Overview          โ”‚ Total Walks (W lines)                                       โ”‚ 23                                                                   โ”‚
 โ”‚ Graph Overview          โ”‚ Unique Samples in Walks                                     โ”‚ 5                                                                    โ”‚
 โ”‚ Segment Statistics      โ”‚ Total Segment Length (bp)                                   โ”‚ 57,119,496                                                           โ”‚
 โ”‚ ...                     โ”‚ ...                                                         โ”‚ ...                                                                  โ”‚
 โ•ฐโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฏ
2. Display by Category

For better readability on large screens, display statistics in separate tables for each category.

$ gratools stats -g Og_cactus.gfa.gz --by-category
 --- GFA Statistics for: Og_cactus ---
        Graph Overview Statistics
 โ•ญโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฎ
 โ”‚ Metric                   โ”‚ Value     โ”‚
 โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ค
 โ”‚ GFA File Name            โ”‚ Og_cactus โ”‚
 โ”‚ ...                      โ”‚ ...       โ”‚
 โ•ฐโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฏ
                                              Segment Statistics Statistics
 โ•ญโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ฌโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฎ
 โ”‚ Metric                                        โ”‚ Value                                                                โ”‚
 โ”œโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ผโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ค
 โ”‚ Total Segment Length (bp)                     โ”‚ 57,119,496                                                           โ”‚
 โ”‚ ...                                           โ”‚ ...                                                                  โ”‚
 โ•ฐโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”ดโ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ”€โ•ฏ
3. Export to CSV

Save the results for downstream analysis in Excel or R. The file is saved directly within the GraTools index directory.

$ gratools stats -g Og_cactus.gfa.gz --save

Metrics Explained๏ƒ

Select a category below to understand the different metrics provided by GraTools.

General information about the GFA file and its primary components.

Metric

Description

GFA File Name

The base name of the input GFA file.

GFA Version

Version declared in the file header (e.g., 1.1).

Total Segments (S lines)

Count of all segment lines (nodes) in the graph.

Total Links (L lines)

Count of all link lines (edges) in the graph.

Total Walks (W lines)

Count of all walk lines, representing paths for samples.

Unique Samples in Walks

Number of distinct sample names found in the walk lines.

Statistics regarding the physical length of the segments (nodes).

Metric

Description

Total Segment Length (bp)

Sum of all unique segment lengths. Also known as Graph Size.

Average Segment Length (bp)

Mean length: Total Segment Length / Total Segments.

Median Segment Length (bp)

Median length across all segments.

Top 5% Stats (Avg/Med)

Average and Median lengths of the longest 5% of segments.

Length Distribution

Binned counts of segments by their base pair length.

Connectivity metrics between segments.

Metric

Description

Max Segment Degree

Highest number of links connected to any single segment.

Average Segment Degree

Mean connectivity: 2 * Total Links / Total Segments.

Self-Links (S1 -> S1)

Links connecting a segment to itself.

Inverted Links

Links connecting segments with opposite orientations (e.g., + to -).

Both Negative Links

Links connecting two segments in reverse-complement orientation.

How genomic sequences traverse the graph.

Metric

Description

Total Path Length (bp)

Sum of all walk lengths. Represents the total sequence content.

Graph Compression Ratio

Total Path Length / Total Segment Length. >1 means redundancy was collapsed.

Max Segments in a Walk

Highest count of nodes in a single walk (W-line).

Sum of First Segments

Sum of the lengths of the starting node of each walk.

How samples are distributed across segments.

Metric

Description

Avg Unique Samples / Seg

Similarity Mean: Mean number of samples passing through a segment.

Median Unique Samples / Seg

Similarity Median: Median number of samples per segment.

Avg Occurrences / Seg

Depth Mean: Average times a segment appears in all walks.

StdDev Unique Samples

Standard deviation of samples per segment.

Topology and connectivity of the whole graph.

Metric

Description

Graph Density

How close the graph is to being complete (fully connected).

Segments/Links Ratio

The balance between nodes and edges.

Dead-End Segments

Segments with only one link (degree 1).

Isolated Segments

Segments with no links at all (degree 0).

Connected Components (CCs)

Number of separate subgraphs.

Largest CC Size (bp)

Sequence length of the largest connected subgraph.

๐Ÿ’ก Pro Tip: Performance

Calculating statistics on very large graphs can be CPU-intensive. Once you have run gratools index, the statistics will be calculated much faster. If you use the --save flag, you can avoid re-calculating them for future reports.

๐Ÿ“‘ Quick Links