Remove duplicate calculation functions after refactoring

[cnicholas]

After refactoring to the Strategy Pattern in #9, we have 4 deprecated standalone functions that duplicate logic now in the Analysis class.

Duplicate Functions (lines 751-1073)

• calculate_statistics_Imr() - duplicates Analysis._calculate_imr()
• calculate_statistics_R() - duplicates Analysis._calculate_r()
• calculate_statistics_S() - duplicates Analysis._calculate_s()
• calculate_statistics_XbarS() - duplicates Analysis._calculate_xbar()

Impact

• ~322 lines of dead code (18% of file)
• Maintenance burden (bugs could be fixed in one place but not the other)
• Confusion about which functions to use

Fix

Remove lines 751-1073 from analysis_dataset.py

Files

• analysis_dataset.py