Reading selected data from .dat file

Hello,

I'm trying to extract data from a .dat file in a particular way. Basically, I need my program to take points from the first part of the data file...

1     8    12    13    14     9     3     2
3     9    14    15    16    10     5     4
.... (and so on)

and select data from the next part of the file corresponding to the numbers above as an "index."

2.0000         0
1.9829    0.1305
1.9319    0.2588
1.7321    0.5000
1.4142    0.7071
0.7654    0.9239
0.0000    1.0000
2.2000         0

As a for instance,

The first line of my file starts with "1 8 12 13..." I need to get coordinates:

2.0000         0
2.2000         0
.. and so on (coordinates corresponding to lines 12 and 13 and on..)

Just imagine it indexed like so,

1. 2.0000         0
2. 1.9829    0.1305
3. 1.9319    0.2588
4. 1.7321    0.5000
5. 1.4142    0.7071
6. 0.7654    0.9239
7. 0.0000    1.0000
8. 2.2000         0

If there is a more efficient way to perform this, please share!

Answer 1

[Star Strider]

Use the ‘First Part’ as indices into the ‘Second Part’.

For example:

FirstPart = [1     8    12    13    14     9     3     2];

NextPart = [2.0000         0
            1.9829    0.1305
            1.9319    0.2588
            1.7321    0.5000
            1.4142    0.7071
            0.7654    0.9239
            0.0000    1.0000
            2.2000         0];

Result = NextPart(FirstPart(1:2),:)

Result =

       2.0000     0.0000
       2.2000     0.0000

Use all of ‘FirstPart’ in your code. I just used ‘FirstPart(1:2)’ because that’s all we have to work with.