Hi,
The simple Perl script manalyze was introduced around v1.5 for the analysis of "multiple" structures. Over the years, I've not been aware of its usage: your question is the first one. As of v2.1beta, I am migrating from Perl to Ruby as the scripting language for 3DNA. Now manalyze and most other not widely used Perl scripts are moved out the $X3DNA/bin/ directory into $X3DNA/perl_scripts/ -- they are obsolete, but kept there for the record.
As of 3DNA v2.1, the Ruby script "x3dna_ensemble" should be used for the analysis of NMR ensembles or MD simulation trajectories. Type -h for detailed info, and run the examples to get familiar with its usage/functionality.
Your attached PDB file contains only one model, so you can use the find_pair/analyze combination to calculate 3DNA parameters. Note, however, your structure has poor geometry, as shown in the image below. As a rule, one should always perform "sanity" check to ensure sensible results.
HTH,
Xiang-Jun