Doubt in array functions

[pgupta]

Hello,

I'm beginner for Labview.

Appearing for CLAD.

Got one doubt on multidimensional array functions.(may be silly question but somehow i'm confused)

As per labview help on all array functions its mentioned everywhere that indexes are referred as Row first, then pages or volume and column is last.

I'm referring to one Labview tutorial manual .. (attached).

On its page 4-21(fig2 for index array function) the elements are indexed according to page, row and column.

What is correct?If we practically do it on Labview then we can find out by moving the cursor over the index that its row or column or page but in exam there will not be any indication. can somebody please clarify.

Thanks for your time.

Best regards,

labview tutorial manual.pdf

[Ton Plomp]

HI pgupta

As per labview help on all array functions its mentioned everywhere that indexes are referred as Row first, then pages or volume and column is last.

That statement (Row, page/volume,column) is definitly wrong, row and column are next to each other at least.

On its page 4-21(fig2 for index array function) the elements are indexed according to page, row and column.

What is correct?If we practically do it on Labview then we can find out by moving the cursor over the index that its row or column or page but in exam there will not be any indication. can somebody please clarify.

I never really cared about that, and I don't think it's neccesary for the exam, you need to make sure that you understand how (auto)-indexing works, how arrays can be constructed etc.

Succes,

Ton

[Saverio]

The "row", "column", and "page" are just terms to aid us poor humans. A 2D array can be viewed as a table, so you can refer to the horizontal thingies are "rows" and the vertical thingies as "columns". With a 3D array you can think of it as having multiple tables stacked on top of each other, and you can consider each of these "sheets" as "pages". They're really just terms to aid in "human-speak". For instance, what do you refer to the 4th index for a 4D array? Chapter? Book? Or, for the physicists out there, time?

[gb119]

There is, however, one case when 'rows' and 'columns' are meaningful and that is when displaying the data of a 2D array in any of the LabVIEW controls that support it - e.g. array controls, tables, intensity plots. Then you do want to know that LabVIEW has a row-major convention.

I can't say I often work in high dimensions, but I was under the impression that if you dragged a n-dimensional array control to show a 2D slice of data that would always be the first two dimensions of the array with the first dimension running down the screen and the second dimension running across the screen and the third/fourth etc dimensions accessing parallel slices of the data set.