The Focal Length Analyzer is a nifty little Bash script that pulls focal length data from digiKam’s database back end and generates nice graphs based on the extracted data.
To perform its magic, the script relies on the sqlite, gnuplot, and imagemagick packages. On Ubuntu and Debian-based distributions, you can install these packages running the apt-get install sqlite3, gnuplot imagemagick command as root. Download then the latest version of the script and make it executable using the chmod o+w focalAnalyzer.sh command. The script accepts two switches: -png and -pdf. Use the -png switch to generate separate graphs for each camera model in the PNG format and the -pdf switch to produce a multi-page PDF file. The script automatically detects whether digiKam uses the SQLite or MySQL database back end, so you don’t need to do anything beyond running the script with the switch you want, for example: ./focalAnalyzer.sh -png