Estrarre porzioni di dati da array

[Hellhammer]

Buongiorno,

sono nuovo del forum e relativamente nuovo del software Labview, premetto che ho effettuato diverse ricerche di soluzioni al problema che sto per porre ma non ho trovato riscontri.

Ho 4 array composti da numeri, tutti i vettori sono delle stesse dimensioni, uno di essi é la variabile indipendente X e gli altri Y1,Y2 e Y3.

L'array X é costituito da sequenze di valori nulli e sequenze di valori non nulli, ciò che devo fare é trovare le porzioni di array in cui X è non nullo ed estrarre tali porzioni in un sub-array di dimensioni minori che contenga appunto solo i valori non nulli di X.

In parallelo devo estrarre da Y1, Y2 e Y3 i dati corrispondenti agli indici di X estratti per ottenere i relativi sub-arrai Y1,Y2 e Y3.

Non ho difficoltà a realizzare una operazione simile in Matlab, mentre non riesco ad implementare in Labview l'analogo codice, qualcuno pò darmi qualche indicazione per risolvere il problema?

Grazie

[Hellhammer]

Hi,

I'm a new user of this forum and quite new user of Labview software; I've been searching for answers at the question i'm going to explain over internet but I can't find a proper one.

I've got 4 arrays of the same length, one is the independent variable X and the others the X-dependent variables Y1, Y2, Y3.

Array X is composed by sequences of zeros and sequences of non zero values: I need to extract into a smaller size subarray the only non zero portions of x. At the same time I need to extract the values corresponding to the indices of the extracted values x frome arrays Y1,Y2,Y3 into 3 sub-arrays.

I can easily write a Matlab code to do that but I can't obtain the same function in Labview, is anybody can help me?

Thanks,

regards.

[jtagg]

Hi Hellhammer,

so you want to remove all 0s from the X array and the corresponding Y arrays?

[edit] the tabs didn't turn out well but these tables are simply 4 columns of values for x, y1, y2, y3...

This is what I understand:

XY1Y2Y3

2567

0291

0452

3166

0560

4946

7132

6454

0112

Should look like this:

XY1Y2Y3

2567

3166

4946

7132

6454

Is it correct?

Regards,

joseph

[Hellhammer]

Hi,

Thank you for the interest in my question.

Yes, it's exactly what I need to do!

I can either delete the x zero parts and relative Y or store the "interesting" parts in new arrays.

Thanks

Regards

[jtagg · Accepted solution]

Hi,

so here's a pretty basic example of how it could be done.

If however you have very large arrays and performance is a problem, then you'll probably want to calculate first the final size of the sub-arrays, create them with full capacity and then fill up by running through the initial arrays selectively. If performance is not an issue though, my example should work well enough.

I haven't done any extensive testing so be careful and check it with a few runs first to make sure it works as expected.

regards,

Joseph

[Hellhammer]

Thank you very much, it worked perfectly!

Regards.