extractDrugMomentOfInertia {Rcpi} | R Documentation

## Descriptor that Calculates the Principal Moments of Inertia and Ratios of the Principal Moments

### Description

Descriptor that Calculates the Principal Moments of Inertia and Ratios of the Principal Moments

### Usage

    extractDrugMomentOfInertia(molecules, silent = TRUE)

### Arguments

`molecules` | Parsed molucule object.
`silent` | Logical. Whether the calculating process should be shown or not, default is `TRUE`.

### Details

A descriptor that calculates the moment of inertia and radius of gyration. Moment of inertia (MI) values characterize the mass distribution of a molecule. Related to the MI values, ratios of the MI values along the three principal axes are also well know modeling variables. This descriptor calculates the MI values along the X, Y and Z axes as well as the ratio's X/Y, X/Z and Y/Z. Finally it also calculates the radius of gyration of the molecule.

### Value

A data frame, each row represents one of the molecules, each column represents one feature. This function returns 7 columns named `MOMI.X`, `MOMI.Y`, `MOMI.Z`, `MOMI.XY`, `MOMI.XZ`, `MOMI.YZ`, `MOMI.R`:

- `MOMI.X` - MI along X axis

- `MOMI.Y` - MI along Y axis

- `MOMI.Z` - MI along Z axis

- `MOMI.XY` - X/Y

- `MOMI.XZ` - X/Z

- `MOMI.YZ` - Y/Z

- `MOMI.R` - Radius of gyration

One important aspect of the algorithm is that if the eigenvalues of the MI tensor are below `1e-3`, then the ratio's are set to a default of 1000.

### Author(s)

Nan Xiao <https://nanx.me>

### Examples

    sdf = system.file('sysdata/OptAA3d.sdf', package = 'Rcpi')

    mol = readMolFromSDF(sdf)
    dat = extractDrugMomentOfInertia(mol)
    head(dat)

[Package Rcpi version 1.20.1 Index]