Connexions

You are here: Home » Content » Auto-Indexing
Content Actions
Lenses

What is a lens?

Lenses

A lens is a custom view of Connexions content. You can think of it as a fancy kind of list that will let you see Connexions through the eyes of organizations and people you trust.

What is in a lens?

Lens makers point to Connexions materials (modules and collections), creating a guide that includes their own comments and descriptive tags about the content.

Who can create a lens?

Any individual Connexions member, a community, or a respected organization.

This content is ...
Affiliated with (?)
This content is either by members of the organizations listed or about topics related to the organizations listed. Click each link to see a list of all content affiliated with the organization.

  • This module is included in aLens by: National InstrumentsAs a part of collection:"LabVIEW Graphical Programming Course"

    Comments:

    "A full introductory course on programming with LabVIEW."

    Click the "National Instruments" link to see all content affiliated with them.

    National Instruments
Also in these lenses

  • This module is included inLens: Connexions Books Available for Print on Demand
    By: ConnexionsAs a part of collection:"LabVIEW Graphical Programming Course"

    Comments:

    "This book is available through the Connexions beta version of print-on-demand from online materials."

    Click the "Printable Books" link to see all content selected in this lens.

    Printable Books
Tags

(?)

These tags come from the endorsement, affiliation, and other lenses that include this content.

Auto-Indexing

Module by: National Instruments

Summary: In this section, you will learn about Auto-Indexing.

If you wire an array to a For Loop or While Loop input tunnel, you can read and process every element in that array by enabling auto-indexing. When you auto-index an array output tunnel, the output array receives a new element from every iteration of the loop. The wire from the output tunnel to the array indicator becomes thicker as it changes to an array at the loop border, and the output tunnel contains square brackets representing an array, as shown in Figure 1.
autoindexon.png
Figure 1
Disable auto-indexing by right-clicking the tunnel and selecting Disable Indexing from the shortcut menu. For example, disable auto-indexing if you need only the last value passed to the tunnel in the previous example.
Because you can use For Loops to process arrays an element at a time, LabVIEW enables auto-indexing by default for every array you wire to a For Loop and for each output tunnel that is created. Auto-indexing for While Loops is disabled by default. To enable auto-indexing, right-click a tunnel and select Enable Indexing from the shortcut menu.

Creating Two-Dimensional Arrays

You can use two For Loops, one inside the other, to create a 2-D array. The outer For Loop creates the row elements, and the inner For Loop creates the column elements, as shown in Figure 2.
2darrayforloop.png
Figure 2

Using Auto-Indexing to Set the For Loop Count

If you enable auto-indexing on an array wired to a For Loop input terminal, LabVIEW sets the count terminal to the array size so you do not need to wire the count terminal.
In Figure 3, the For Loop executes a number of times equal to the number of elements in the array. Normally, if the count terminal of the For Loop is not wired, the run arrow is broken. However, in this case the run arrow is not broken.
autoindexinput.png
Figure 3
If you enable auto-indexing for more than one tunnel or if you wire the count terminal, the count changes to the smaller of the two. For example, if you wire an array with 10 10 elements to a For Loop input tunnel and you set the count terminal to 15 15, the loop executes only 10 10 times.

Comments, questions, feedback, criticisms?

Discussion forum

Send feedback