Reference to Array of Clusters with an array element

Hi,
I have an array of clusters CONTROL (calling it as "top level cluster array") with one of the cluster elements being a cluster array (please see attached).
I plan to pass "Reference" of this top level cluster to different VIs (like add element VI, insert element VI, delete element VI etc) and access (add/modify delete) the elements in this array.
In my code, how do I typecast the Array Element (cluster) to the inner cluster (as shown in the figure) ?
I am using LV RT on PXI.
Solved!
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You cannot use references in the same way that you use pointers around in C. LabVIEW does not manage memory in the same way that C does. This is actually a good thing, though C programmers find it "cumbersome" or "restrictive". I have also programmed in C, and frankly I prefer LabVIEW's memory management any day of the week.
You had not initially mentioned that this was going to be done in multiple places at (potentially) the same time. Given that, my recommendation is to look into using Action Engines. They provide a means of basically providing a one-location acccess for your data. By using a single VI to access/modify your data you preclude the generation of race conditions. You may also want to join this with the concept of using variants to provide a means to quickly find your data rather than looping to find the element you're interested in. This technique has been around for a while and it has been discussed before. There are examples floating around. Will need to check to find one.
As for your question regarding using the reference method which you tried to employ in your initial approach, that's simply not going to gain you anything. You will still be creating buffers when you try to access the cluster elements. But you already have this information in the array inside the outer for loop, so you're just creating unnecessary extra programming for yourself.

Similar Messages

How do i send an array of clusters with variable size over TCP/IP?

Hi,
I'm trying to send an array of clusters with varible size over TCP/IP,. But I'm facing the following problems:
1) I need to accept the size of array data from the user and increase the size dynamically.
I'm doing this using the property node but how do I convey the new size to my TCP read?
2) I need to wire an input to my 'bytes to read' of the TCP read.
But the number of bytes to read changes dynamically
How do I ensure the correct number of bytes are read and reflected on the client side?
3) Is there anyway I can use global varibles over a network such that their values are updated just as if they would on one computer?
Will be a great help if someone posts a solution!
Thank you...

twilightfan wrote:
Altenbach,
... xml string. ...number of columns that I'm varying using property node s... I solved these problems by using a local variable as the type input ...o TCP read is creating a problem.... second TCP read gets truncated data because
its no longer just the first four bytes that specify the length of the data, it could be more as my array of cluster can be pretty huge.
Instead of writing long and complicated sentences that make little sense, why don't you simply show us your code?
What does any of this have to do with xml strings???? I don't see how using a local variable as type input changes anything. The user cannot interact with "property nodes", just with controls. Please clarify. Once the array of clusters is flattened to a string you only have one size that describes the size of the data, no matter how huge it is (as long as it is within the limits of I32). Similarly, you read the string of that same defined length and form the array of clusters from it. How big are the strings? What is your definition of "huge"?
Here's is my earlier code, but now dealing with an array of clusters. Not much of a change. Since you have columns, you want 2D. Add as many diensions you want, but make sure that the control, diagram constant, and indicator all match.
The snipped shows for a 1D array, while the attached VI shows the same for a 2D array. Same difference.
Message Edited by altenbach on 01-31-2010 01:13 AM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
FlattenArrayOfClusters.vi ‏12 KB
ioclusters3MOD.png ‏25 KB

Trying to clear an array of clusters with image info from memory - overflowing!

I am using a cluster with IMAQ interface name, session info, image array, and individual image and creating an array of that cluster. I try to clear the cluster by deleting the array elements, read an array of images, save them, and repeat the loop. Over time, though the arrays are tearing through all available RAM. I tried removing local variables (which I understand would save a copy of the entire array to memory every loop iteration) and had no luck - actually the code hangs now on the write function, where it thinks there is no image data. I didn't think I changed anything other than to direct wire where there had been local vars to pass information from one part of the sequence to the next. Help! (screenshots of code attached).
Attachments:
framegrab sequence 1.jpg ‏8 KB
framegrab sequence 1a.jpg ‏47 KB
framegrab sequence 2 - grab and save.jpg ‏149 KB

Hi, Nasgul,
Not sure where you have resources leak - from your screenshots its not clear.
But one is clear - you may not understand that IMAQ Images in LabVIEW passed by references. So, if you want to create array of images, then for each element IMAQ Create should be called with different name, otherwise all elements referred to the same image. For example, if IMAQ Dispose will be called for the first elementh of the array, then other 9 images will be automatically invalid.
Compare two code snippets below:
Common recipe for solving troubles with resources - reduce your application step by step by isolating parts of the code with case structures until application will be stable. Then you will found part of code which caused memory leak.
best regards,
Andrey.

Array of Clusters with Graph - Y Scale Change Event

Hello everyone
I have a Array of Clusters with a Graph inside each cluster. I need to trigger a event when the user type a new value on the graphs' Y scale and hit "Enter" to apply the change. Any ideas how to trigger that?
I am not considering the "mouse enter" event because I have other events linked with that already.
Thanks
Dan07
Solved!
Go to Solution.

dan07 wrote:
I think that I was not clear. Sorry. Lets thing about two arrays of clusters with graphs: Array of clusters 1 and Array of clusters 2. Both of them have their own graphs insides the clusters.
I want to do the same thing that you told me to do, but with two arrays of clusters instead of one. Changing the scale range of any graph of array of cluster 1 will trigger case A of event structure (just an example), and changing the scale range of any graph of array of clusters 2 will trigger case B of event structure (just an example again).
Then try the following. Dynamic Event Registration nodes are expandable:
a.lia-user-name-link[href="/t5/user/viewprofilepage/user-id/88938"] {color: black;} a.lia-user-name-link[href="/t5/user/viewprofilepage/user-id/88938"]:after {content: '';} .jrd-sig {height: 80px; overflow: visible;} .jrd-sig-deploy {float:left; opacity:0.2;} .jrd-sig-img {float:right; opacity:0.2;} .jrd-sig-img:hover {opacity:0.8;} .jrd-sig-deploy:hover {opacity:0.8;}

How to set the value of an array element (not the complete array) by using a reference?

My situation is that I have an array of clusters on the front panel. Each element is used for a particular test setup, so if the array size is three, it means we have three identical test setups that can be used. The cluster contains two string controls and a button: 'device ID' string, 'start' button and 'status' string.
In order to keep the diagrams simple, I would like to use a reference to the array as input into a subvi. This subvi will then modify a particular element in the array (i.e. set the 'status' string).
The first problem I encounter is that I can not select an array element to write to by using the reference. I have tried setting the 'Selection s
tart[]' and 'Selection size[]' properties and then querying the 'Array element' to get the proper element.
If I do this, the VI always seems to write to the element which the user has selected (i.e. the element that contains the cursor) instead of the one I am trying to select. I also have not found any other possible use for the 'Selection' properties, so I wonder if I am doing something wrong.
Of course I can use the 'value' property to get all elements, and then use the replace array element with an index value, but this defeats the purpose of leaving all other elements untouched.
I had hoped to use this method specifically to avoid overwriting other array elements (such as happens with the replace array element) because the user might be modifying the second array element while I want to modify the first.
My current solution is to split the array into two arrays: one control and one indicator (I guess that's really how it should be done ;-) but I'd still like to know ho
w to change a single element in an array without affecting the others by using a reference in case I can use it elsewhere.

> My situation is that I have an array of clusters on the front panel.
> Each element is used for a particular test setup, so if the array size
> is three, it means we have three identical test setups that can be
> used. The cluster contains two string controls and a button: 'device
> ID' string, 'start' button and 'status' string.
>
> In order to keep the diagrams simple, I would like to use a reference
> to the array as input into a subvi. This subvi will then modify a
> particular element in the array (i.e. set the 'status' string).
>
It isn't possible to get a reference to a particular element within an
array. There is only one reference to the one control that represents
all elements in the array.
While it may seem better to use references to update
an element within
an array, it shouldn't really be necessary, and it can also lead to
race conditions. If you write to an element that has the
possibility of the user changing, whether you write with a local, a
reference, or any other means, there is a race condition between the
diagram and the user. LV will help with this to a certain extent,
especially for controls that take awhile to edit like ones that use
the keyboard. In these cases, if the user has already started entering
text, it will not be overwritten by the new value unless the key focus
is taken away from the control first. It is similar when moving a slider
or other value changes using the mouse. LV will write to the other values,
but will not rip the slider out of the user's hand.
To completely avoid race conditions, you can split the array into user
fields and indicators that are located underneath them. Or, if some
controls act as both, you can do like Excel. You don't directly type
into the cell. You choose w
hich cell to edit, but you modify another
location. When the edit is completed, it is incorporated into the
display so that it is never lost.
Greg McKaskle

Type defined array of clusters for holding configuration data - setting default values for each array element

Hi,
I was wondering if I could get some information and opinions about using a type defined array of clusters to hold configuration data. I am creating a program to test multiple DUTs and wanted to have a type defined control for each DUT containing the information needed to create the DAQmx tasks for all of the signals for that DUT. I am wanting to do this so that the data is hard-coded and not in a file that the user could mess up.
The type def controls are then put in a subVI that chooses the appropriate one based on the DUT Type enumeration wired to a case structure.
I am having problems with the type defined control. I am seeing issues when attempting to save a unique configuration to each array element in the array of clusters. Somehow it worked to begin with, but now clicking "Data Operations --> Make Current value default" on individual elements of the cluster or the entire cluster (array element) is not saving the data when I re-open the type def control. What am I doing wrong? Am I trying to do something with arrays of clusters that I should not be doing?
I have attached one of the type defined controls for reference. I tried changing it to Strict to see if that helped, but no luck.
To reproduce, change the resource string for array element 0 and make the new value the default value. Then close the type def, and re-open it. The old value is still present in that element. The VI is saved in LabVIEW 2012.
Solved!
Go to Solution.
Attachments:
CM_AnalogInputs.ctl ‏11 KB

Values of a typedef are not proprigated to instances of the control. THey will pick it up if created AFTER the data values have been changed. THey will not get updated with future changes. You should either create a VI specifically for hardcoding your values or implement a file based initialization. The file based would be much better and more flexible. If you don't want users to modify the data simply encrypt it. There is a noce blowfish library you can download.
Mark Yedinak
"Does anyone know where the love of God goes when the waves turn the minutes to hours?"
Wreck of the Edmund Fitzgerald - Gordon Lightfoot

Java - Instance variable that can reference an array of integers?

Hello,
I have the following question in my assignment:
Your first task is to declare a private instance variable called cGroups that can
reference an array of integers. You should then write a constructor for GameN. This should
take a suitable array as its argument which should be used to initialise cGroups.
In order to test your code for declaring and initialising cGroups, you should execute
the following code
int[] coin = {2, 8, 5};
GameN aGame;
aGame = new GameN(coins);
and I have complete the code below but it's not working. maybe I'm reading it wrong or
not understandin something. Could someone correct it? or put me on the right lines
private int[] cGroups = new int[]
public GameN(int group1, int group2, int group3)
super();
this.cGroups = {group1, group2, group3};
}

ShockUK wrote:
I've changed it to
private int[] coinGroups = new int[] {1};
public Nim(int group1, int group2, int group3)
super();
int[] coinGroups = {group1, group2, group3};
}But I still get the same error "Constructor error: Can't find constructor: Nim( [I ) in class: Nim"
Look at the line that error is pointing at. You're trying to use a constructor that doesn't exist. This is not a problem with creating an array.

Lots of blank space when printing array with only last element printed

I have a slight problem I have been trying to figure it out for days but can't see where my problem is, its probably staring me in the face but just can't seem to see it.
I am trying to print out my 2 dimensional array outdie my try block. Inside the trying block I have two for loops in for the arrays. Within the second for loop I have a while to put token from Stringtokeniser into my 2 arrays. When I print my arrays in this while bit it prints fine however when I print outside the try block it only print the last element and lots of blank space before the element.
Below is the code, hope you guys can see the problem. Thank you in advance
   import java.io.*;
   import java.net.*;
   import java.lang.*;
   import java.util.*;
   import javax.swing.*;
   public class javaflights4
      public static final String MESSAGE_SEPERATOR = "#";
      public static final String MESSAGE_SEPERATOR1 = "*";
      public static void main(String[] args) throws IOException
         String data = null;
         File file;
         BufferedReader reader = null;
         file = new File("datafile.txt");
         String flights[] [];
               //String flightdata[];
         flights = new String[21][7];
         int x = 0;
               //flightdata = new String[7];
         int y = 0;
         try
            reader = new BufferedReader(new FileReader(file));
            //data = reader.readLine();
            while((data = reader.readLine())!= null)
               data.trim();
               StringTokenizer tokenised = new StringTokenizer(data, MESSAGE_SEPERATOR1);
               for(x = 0; x<=flights.length; x++)
                  for(y = 0; y<=flights.length; y++)
                     while(tokenised.hasMoreTokens())
                        //System.out.println(tokenised.nextToken());
                        flights [x] [y] = tokenised.nextToken();
                        //System.out.print("*"+ flights [x] [y]+"&");
               System.out.println();
            catch(ArrayIndexOutOfBoundsException e1)
               System.out.println("error at " + e1);
            catch(Exception e)
            finally
               try
                  reader.close();
                  catch(Exception e)
         int i = 0;
         int j = 0;
         System.out.print(flights [j]);
//System.out.println();

A number of problems.
First, I bet you see a lot of "error at" messages, don't you? You create a 21x7 array, then go through the first array up to 21, going through the second one all the way to 21 as well.
your second for loop should go to flights[x].length, not flights.length. That will eliminate the need for ArrayIndexOutOfBounds checking, which should have been an indication that you were doing something wrong.
Second, when you get to flights[0][0] (the very first iteration of the inner loop) you are taking every element from the StringTokenizer and setting flights[0][0] to each, thereby overwriting the previous one. There will be nothing in the StringTokenizer left for any of the other (21x7)-1=146 array elements. At the end of all the loops, the very first element in the array (flights[0][0]) should contain the last token in the file.
At the end, you only print the first element (i=0, j=0, println(flight[ i][j])) which explains why you see the last element from the file.
I'm assuming you have a file with 21 lines, each of which has 7 items on the line. Here is some pseudo-code to help you out:
count the lines
reset the file
create a 2d array with the first dimension set to the number of lines.
int i = 0;
while (read a line) {
Tokenize the line;
count the tokens;
create an array whose size is the number of tokens;
stuff the tokens into the array;
set flights[i++] to this array;
}

A basic question/problem with array element as undefined

Hello everybody,
thank you for looking at my problem. I'm very new to scripting and javaScript and I've encountered a strange problem. I'm always trying to solve all my problem myself, with documentation (it help to learn) or in the last instance with help of google. But in this case I am stuck. I'm sure its something very simple and elementary.
Here I have a code which simply loads a text file (txt), loads the content of the file in to a "var content". This text file contents a font family name, each name on a separate line, like:
Albertus
Antenna
Antique
Arial
Arimo
Avant
Barber1
Barber2
Barber3
Barber4
Birch
Blackoak ...etc
Now, I loop trough the content variable, extract each letter and add it to the "fontList[i]" array. If the character is a line break the fontList[i] array adds another element (i = i + 1); That's how I separate every single name into its own array element;
The problem which I am having is, when I loop trough the fontList array and $.writeln(fontList[i]) the result in the console is:
undefinedAlbertus
undefinedAntenna
undefinedAntique
undefinedArial ...etc.
I seriously don't get it, where the undefined is coming from? As far as I have tested each digit being added into the array element, I can't see anything out of ordinary.
Here is my code:
#target illustrator
var doc = app.documents.add();
//open file
var myFile = new File ("c:/ScriptFiles/installedFonts-Families.txt");
var openFile = myFile.open("r");
//check if open
if(openFile == true){
    $.writeln("The file has loaded")}
else {$.writeln("The file did not load, check the name or the path");}
//load the file content into a variable
var content = myFile.read();
myFile.close();
var ch;
var x = 0;
var fontList = [];
for (var i = 0; i < content.length; i++) {
    ch = content.charAt (i);
        if((ch) !== (String.fromCharCode(10))) {
            fontList[x] += ch;
        else {
            x ++;
for ( i = 0; i < fontList.length; i++) {
   $.writeln(fontList[i]);
doc.close (SaveOptions.DONOTSAVECHANGES);
Thank you for any help or explanation. If you have any advice on how to improve my practices or any hint, please feel free to say. Thank you

CarlosCantos wrote an amazing script a while back (2013) that may help you in your endeavor. Below is his code, I had nothing to do with this other then give him praise and I hope it doesn't offend him since it was pasted on the forums here.
This has helped me do something similar to what your doing.
Thanks again CarlosCanto
// script.name = fontList.jsx;
// script.description = creates a document and makes a list of all fonts seen by Illustrator;
// script.requirements = none; // runs on CS4 and newer;
// script.parent = CarlosCanto // 02/17/2013;
// script.elegant = false;
#target illustrator
var edgeSpacing = 10;
var columnSpacing = 195;
var docPreset = new DocumentPreset;
docPreset.width = 800;
docPreset.height = 600;
var idoc = documents.addDocument(DocumentColorSpace.CMYK, docPreset);
var x = edgeSpacing;
var yyy = (idoc.height - edgeSpacing);
var fontCount = textFonts.length;
var col = 1;
var ABcount = 1;
for(var i=0; i<fontCount; i++) {
    sFontName = textFonts[i].name;
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    itext.textRange.characterAttributes.size = 12;
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    itext.left = x;
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            var abtop = ab[1];
            var ableft = ab[0];
            var abright = ab[2];
            var abbottom = ab[3];
            var ntop = abtop;
            var nleft = abright+edgeSpacing;
            var nbottom = abbottom;
            var nright = abright-ableft+nleft;
            var abRect = [nleft, ntop, nright, nbottom];
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Best way to iniitialize a queue with array elements

Hi Guys
I'm looking for a bit of performance optimization..
I'm developing a noise measurement application using LV8.6 and Win Xp /Win 7.
To put it very simple I have a loop that samples, and a loop that does the math. data is shipped in a queue, producer / consumer style.
So far so good.. Question is - is there a specific and more optimized way to declare this queue?
I was wondering if declaring the queue with an initialized array element of a fixed size (the number of samples pr. read from the sound card will be known at runtime) would produce a queue that would be less heavy on dynamic allocation of memory compared to a queue obtained using a simple control no values.
I've attached a screen dump to maybe make the question more obvious..
I've been thru the "clear as mud" thread, as recommended in other threads that covers this topic - but i gets very high tech, and I kind of lost my way in it.. So looking for a more simple "you should use solution #x, because..."
Thank you in advance.
Solved!
Go to Solution.

I believe (but am not sure) RT FIFOs will allocate this memory for you ahead of time. But, remember they are not deterministic on windows. You need to wire an array constant of the correct size into the FIFO read function also to avoid memory allocation, which is easy to overlook. It's worth looking into, if nothing else, assuming you have RT functions available. WIth this method, the queue size needs to be set, and you run the risk of overflowing and losing elements if not handled correctly.
Just throwing other options out there.
CLA, LabVIEW Versions 2010-2013

How to make 1D Array but with only one element filled in Real Time

Hi folks,
here I am with another question. I want to implement an prediction discrete state space observer which is going to run on a CRIO real time target. I am going to do it just like in the example which comes with LV.
I have some questions regarding the input and outputs which in the example those are "dummy".
My model is a SISO model, but the function "Construct SS model" returns parameters (A,B,C,D Matrices) as 2D arrays, so once you connect the cluster model into the Discrete Observer model, it takes y and u as 1D arrays despite of the fact that there is a SISO model.
I realized that the function I am using in the simulations, uses 1D arrays but with only one element filled:
Does anyone knows how to implement such 1D arrays in Real Time? I guess the way to do it is preallocating one array of zeros of size 1, and then recirculating it through some SR, and replacing the element with my real input and output, but at the dummy.vi, they are using a simple "build array"
function.

Ok, I did it that way. But I am facing another problem right now...
At some point the Discrete Observer return a NAN array, you will see the code in the code snippet?
I get rid of that component by component, but the observer gets "stuck" in it. So my Control law is zero... but the state stimate is NAN.
Also I am attaching the VI.
I do not know why, since in the simulation program all runs well. any thoughts? Maybe the internal numeric precision of the State Space Model?
Attachments:
RT - Pole Placement + Complete Observer.vi ‏40 KB

Trying to use .split with an array element

I have tried multiple ways to split an array element into its components that are separated with a space with this code:
public static void compareHand(String[] hand){
        for (int i = 0; i < hand.length; i++){
            System.out.println(i);
            System.out.println(hand);
String[] tokens = hand[i].split("\\s");
System.out.println(tokens.length);
for (int j = 0; j < tokens.length; j++){
System.out.println(tokens);
I keep getting strange output like the following:
King of Spades
3
[Ljava.lang.String;@10b62c9
[Ljava.lang.String;@10b62c9
[Ljava.lang.String;@10b62c9
where I am expecting:
King of Spades
3
King
of
Spades
Any ideas where I am going wrong?

public static void compareHand(String[] hand){
         for (int i = 0; i < hand.length; i++){
              System.out.println(i);
              System.out.println(hand);
String[] tokens = hand[i].split("\\s");
System.out.println(tokens.length);
for (int j = 0; j < tokens.length; j++){
System.out.println(tokens); // your error is on this line. Hint ... System.out.println(tokens[...]);

Crash when use indexe array with in place element structure

Hello !
I have a problem with in place element structure. I want index a waveform array (16 elements) and when i execute or save that labview close....
I dont have problem with waveform array 15 elements or less, but i need index 16 elements...
Thanks for your help !!!
Solved!
Go to Solution.
Attachments:
Test.PNG ‏8 KB

I give you my code but it work because i used a waveform array with only 15 elements. I can't save or execute with 16 elements...
So add it (like picture Test.png) and you will see.
Thank you
Attachments:
Test.vi ‏25 KB

How to check string array elements with a string with in one forEach tag ?

Hi All,
I am new to JSTL and EL. I need to change the following Java code into JSTL and EL.. I struggled to change this code into JSTL.
How can i change the if loop which tests the string array element with one bean property ?
-------------------------------------------------------------------------------------------------------------for(int j=0 ; j < iSelectedCount; j++)
if(strSelectedRoleId[j].equals(lineRole.getRoleID()))
isAvailable = true;
Please help me on this.
It is very urgent......
Thank you for ur help,
Natraj

import java.util.Calendar;
Calendar rightNow = Calendar.getInstance(); // gets the current date and time to millisec
Calendar earlyTime = Calendar.getInstance().set(Calendar.HOUR_OF_DAY, 6).set(Calendar.MINUTE, 30);
Calendar lateTime = Calendar.getInstance().set(Calendar.HOUR_OF_DAY, 8).set(Calendar.MINUTE, 0);
if (rightNow.compareTo(earlyTime)> 0 && rightNow.compareTo(lateTime) < 0){
// do something
}Try this.

The below vi is not giving me what I want. If I select 2 with maximum number of 3 then there are 3 array elements display that is correct but if I select 8 with the same maximum number of 3 then only 1 array element display. Why is that?

The below vi is not giving me what I want. If I select 2 with maximum number of 3 then there are 3 array elements display that is correct but if I select 8 with the same maximum number of 3 then only 1 array element display. Why is that?
Attachments:
test2.vi ‏29 KB

It's because in case 2 you hold the array build result from the previous loop iteration in a shift register...in case 8 you do not...
You say that if you set the maximum number to three it will produce an array with three elements, that is not correct, it will run when the iteration index is 0,1,2 and 3...resulting in 4 elements. If you want 3 you need to decrement the maximum number to 2. The same goes for case 8.
MTO

Reference to Array of Clusters with an array element

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