I can't figoure out how to write an ASCII file for a 3D box (temperature perturbation)

ASPECT
1

Dear users,

I can’t figure out how to correctly write the ASCII file for a 3D temperature perturbation box.

This is the example given:

# Test data for layered ascii data initial temperature conditions.
# The following data defines a surface in 3D cartesian space which
# will be used to define the 500 K isotherm in
# tests/ascii_data_layered_initial_temperature_3d_box.prm and
# tests/ascii_data_layered_initial_temperature_piecewise_constant_3d_box.prm.
# Only next line is parsed in format: [nx] [ny] because of keyword "POINTS:"
# POINTS: 3 3
# Columns: x y z temperature[K]
0.     0.     550000. 500.
300000 0.     550000. 500.
600000 0.     550000. 500.
0.     300000 500000. 500.
300000 300000 500000. 500.
600000 300000 500000. 500.
0.     600000 600000. 500.
300000 600000 600000. 500.
600000 600000 600000. 500.

For every X cycle, Y goes from 0 to MAX, but I didn’t understand how Z evolves. In one cycle it is 555000, in the second the value drops to 500000, and then it increases to 600000. I understand that these are constants, but I don’t understand the logic behind the increasing and decreasing values.

Also, for a 3D box, I would expect 3 points, not 2.

So, I am asking for the logic of Z to write the ASCII file correctly.

Thank you in advance,

Francesco

2

Dear Francesco,

That is an example input file for layered initial temperature input. This is described in the relevant section of the manual: Initial temperature model — ASPECT 2.6.0-pre

The logic is that the first two columns define x and y coordinates of an isosurface, the third column defines the local z-coordinate of the isosurface, and the fourth column defines the isosurface temperature. More than one isosurface can be defined.

Best wishes,
Bob