retstr = skyline_in(ins)

The MATLAB web server calls this function when the topographic shielding data input form (skyline_input.html) is submitted. It takes as input a structure containing string variables, which is supplied by the MATLAB web server. It returns a text string consisting of an output HTML document containing the results of the erosion rate calculation. The documentation for the MATLAB web server describes this process in more detail.

The input structure `ins`

contains the following fields. All are string variables. These have the same names as the data-entry fields in the HTML input form.

ins.str_strike | Strike of sampled surface (degrees) |

ins.str_dip | Dip of sampled surface |

ins.str_az | String of space-separated azimuths |

ins.str_el | String of space-separated horizon angles |

Note that whole number degrees are required for all the inputs (on the basis that measurements with a greater precision than this are highly unlikely). Decimal degrees will be rejected.

The majority of this function consists of routines that check the input data to make sure it is in the expected form and is within expected bounds, and convert string variables to numerical values. After the data checking is complete, the function passes data to the function `skyline.m`

, which actually carries out the erosion rate calculation and returns the result. Finally, this function assembles the output data, generates the required plots, and inserts the output data into the output HTML template.