[ferret_users] Point data & closest matching within an ASCII grid

[Khoa Nguyen <instcode@xxxxxxxxx>]

Hi all,

I'm getting start with Ferret these days and having the following problem which I couldn't figure out how to solve it.

I have two external data files: grid.txt & coords.txt which contain:
- Grid: row, column, value
- Coords: row, column

Currently, I load the data in the "grid.txt" file into a grid by x-axis. Now, I want to get an array of values from the original grid by matching (and doing some linear interpolation if needed) the (row, column) in the "coords.txt" file with the (row, column) in the grid.

How could this be done?
Thank you very much in advance.

Regards,
Khoa Nguyen

P/S: The sample data here is a bit stupid, it's for testing purpose:

Grid.txt
1    1    12
1    2    12
1    3    234
1    4    54
1    5    45
2    1    23
2    2    3
2    3    56
2    4    67
2    5    78
3    1    12
3    2    23
3    3    6
3    4    34
3    5    67
4    1    8
4    2    90
4    3    67
4    4    45
4    5    23
5    1    12
5    2    54
5    3    56
5    4    76
5    5    76

Coords.txt
1.5   2.0
3.0   3.1
4.0   1.2
2.1   3.5