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