# ARTS built-in documentation server

## Workspace Method diameter_maxFromDiameter_volume_equ

### Description

Calculates maximum and area equivalent diameters from volume
equivalent diameter.
This is primarily a help function for using the T-matrix method
and only a few particle shapes are handled.
For shapes handled and further comments on the input arguments, see
scat_data_singleTmatrix.
Area equivalent diameter is the equivalent sphere diameter
corresponding to the "maximum axial area". This is the largest
cross-sectional area of the particle, observed either along the
particle's main axis or in the perpendicular direction. That is,
for a cylinder having diameter d and thickness h, this area is
either (pi*d^2)/4 or (h*d).

**Authors: **Johan Strandgren, Patrick Eriksson

### Synopsis

diameter_maxFromDiameter_volume_equ( | diameter_max, diameter_area_equ, shape, diameter_volume_equ, aspect_ratio ) |

### Variables

GOUT | diameter_max | (Numeric) | Maximum dimension of the particle. |

GOUT | diameter_area_equ | (Numeric) | Maximum axial area equivalent diameter of the particle, see above. |

GIN | shape | (String) | Particle shape. |

GIN | diameter_volume_equ | (Numeric) | Particle equivalent volume diameter. |

GIN | aspect_ratio | (Numeric) | Particle aspect ratio. |