### OrCa: Orthogonality Calculator

### Developing orthogonal separations requires
being able to measure orthogonality

How do you do that?

**Mark's
Presentation on Orthogonal Separations at Pittcon**

also see: M. R. Schure, J. M. Davis Orthogonal
Separations:

Comparison of Orthogonality Metrics through Statistical Analysis

Journal of Chromatography A, 1414 (2015) 60-76.

**Send inquiries regarding
purchasing OrCa or getting a trial copy to kroungold.analytical@gmail.com**

### OrCa allows the calculation of various orthogonality metrics
for both single dimension

and multidimensional chromatography. The features present in OrCa include:

### For 1D chromatography:

### • Calculation of the box counting (fractal) dimension,
an easy to use and interpret metric

• Nearest neighbor statistics

• Entropy from information theory with two discretization schemes

### For 2D chromatography:

### • Calculation of the box counting (fractal) dimension,
an easy to use and interpret metric

• Pearson, Kendall and Spearman correlation coefficients

• Gilar’s surface coverage with two discretization schemes

• Relative convex hull area

• Nearest neighbor statistics

• Entropy per dimension, 2D entropy, mutual information and percent orthogonality

from information theory with two discretization schemes

This desktop application runs under Windows XP and Windows 7. It takes retention
time data from a file and gives you all of the orthogonality metrics listed
above.

The retention data is stored as a list of single retention times (1D) or a
comma-separated variables list of retention time pairs (2D). The output is available
as a copy-and-paste report-style output and a copy-and-paste spreadsheet into
Excel. In addition, the plotting for 2D chromatography includes displaying the
minimal spanning tree, the convex hull and the bins occupied for Gilar's surface
coverage scheme.

As with all Kroungold software, any bug found will be fixed immediately.