Atomic operation on array elements

For array elements of primitive types (32 bits and less): byte, short, int. Are array operations atomic?
For example, define byte b[] = new byte[1];
thread A executes b[0]++; thread B reads b[0]. or both threads writing..
Question:
1 Is it possible to get an incostintent value reading b[0].
2. Do you think JVM or OS know that two threads work on the same element and synchronizes them to ensure value consistency?
As a consequence of synchronizatrion, is there speed difference if I have two threads writing to b[0] and b[1] OR two threads writing to same element b[0]. I checked, there seems to be none.

Suppose I do not want to synchronize access to array
elements. Then you can't guarantee correct behavior of things like ++.
It's going degrade performanceHave you measured this, so that you know it will be a problem, or are you just assuming?
but would
like to understand whether JVM enforces the same
atomic rule on array elements as does with variables.++ is NOT atomic on anything--variables or array elements. All threading issues are the same for array elements as for variables.
Can anynody comment on performance? Is it faster to
modify different elements of array versus the same
index? shouldn't the same be slower?Try it yourself and see if you can even see a meaningful difference.

Similar Messages

Are the read and write operations atomic for an array in a local variable.

Hi,
I would like to know when you access an array in a local variable, is it an atomic operation?
Thanks,
Mat

Thanks for the comments. I agree with you. However, I my case, race conditions and synchronization are not issues. Therefore, the only thing that matters to me is that the write and read operation of the array must be atomic. I know that I can implement that with a LV2 style global but I want to avoid it if possible.
If writing and reading to an array are atomic operations then I can simply use local or global variables.
All I need to know is: Is reading or writing an array in a local variable an atomic operation?
Thanks,
Mat

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

Sum array elements not working

I am trying to output the average % standard deviation per point for a series of data sets. To do this I want to use the sum array elements function. The program I have written should work I am pretty sure, but when I watch data flow through it, 1000 points get input into the sum function and NaN comes out. What could cause an error like this? I have tried inverting my array, etc. Is there a limit to the number of points the function can take? Or to the precision of the points being input? Thanks, this is driving me crazy!
[I renamed the file and attached it again so you can open it - Molly K]
Message Edited by Support on 07-06-2005 08:23 AM
Attachments:
Average % Std Dev.vi ‏23 KB
Average.vi ‏23 KB

Any arithmetic operation on a NaN value is invalid and must result in NaN as
well. You probably need to make sure first that your array doesn't
contain NaN, Inf, and -Inf.
Rolf Kalbermatter
Message Edited by rolfk on 07-05-2005 11:37 AM
Rolf Kalbermatter
CIT Engineering Netherlands
a division of Test & Measurement Solutions

Change array element "initialized" property

I'm a newcomer here. And it is a simple question.
The aim of this part is to save the array data.
You can see that if the array element is uninitialized, it won't be saved to spreadsheet, which saves space in the disk. So can I change the "initialized" property of this array element back to unitialized?
Thanks
Solved!
Go to Solution.

You can "right-click the element...data operations...delete element".
(This has nothing to do with "uninitialized". The size of the array is indicated by the bright elements, the dull elements are outside the valid range, which has nothing to do with the size of the container. Your first array has two elements and your second array has three elements.)
LabVIEW Champion . Do more with less code and in less time .

Strange behaviour of "And array Elements"

If u connect an empty boolean array to "And Array Elements" function, The output is "True" !. Is this correct?. Is there something wrong ?. Please Help.

Hi J.A.C
This is correct.This is an explanation I've found: "This behavior is intentiional, and stems from elementary Boolean logic. The Boolean algebra primitives are analogous to numeric operations are integers. Just as the identity element for addition is 0, and for multiplication, 1; the identity for Boolean OR is FALSE, and for AND, TRUE. For example, x^0 == 1; that is, x times itself zero times is by definition 1. For the same reason boolean x ANDed with itself zero times is TRUE."
If this is not acceptable for your application, then just use the "Array Size" VI first to check if you've an empty Array (Array size=0) and then you can pass or not the array to the "And Array Elements" function.
Hope this helps.
Luca
Regards,
Luca

How to modify array elements from a separate class?

I am trying to modify array elements in a class which populates these fields by reading in a text file. I have got mutator methods to modify the array elements and they work fine in the same class.
public class Outlet {
     private Outlet[] outlet;
     private String outletName;
     private int phoneNumber;
     private int category;
     private int operatingDays;
static final int DEFAULT = 99;
     public void setPhoneNumber(int newPhoneNumber) {
          phoneNumber = newPhoneNumber;
     public void setCategory(int newCategory) {
          category = newCategory;
     public void setOperatingDays(int newOperatingDays) {
          operatingDays = newOperatingDays;
public static void readFile(Outlet[] outlet) throws FileNotFoundException {
          Scanner inFile = new Scanner(new FileReader("outlets.txt"));
          int rowNo = 0;
          int i = 0;
          String outletValue;
          while (inFile.hasNext() && rowNo < MAXOUTLETS) {
               outlet[rowNo] = new Outlet();
               outletValue = inFile.nextLine();
               outlet[rowNo].setOutletName(outletValue.toUpperCase());
               outlet[rowNo].setPhoneNumber(DEFAULT);
               outlet[rowNo].setCategory(DEFAULT);
               outlet[rowNo].setOperatingDays(DEFAULT);
          inFile.close();
     public static void displayUnassignedOutlets(Outlet[] outlet) {
          int i = 0;
          System.out.println("Showing all unassigned Outlets");
          System.out.println(STARS);
          for (i = 0; i < MAXOUTLETS; i++ ) {
               if (outlet.getCategory() == DEFAULT) {
               System.out.println("\nOutlet Number: " + (i + 1) + "\t" +
                         outlet[i].getOutletName());
Now in the other class that I want to modify the array elements I use the following code but I get an error that "The expression type must be an array but a Class ' Outlet' is resolved".
So how can I modify the array elements? What do I have to instantiate to get the following code to work?
public class Franchise {
     private Franchise[] franchise;
     public Outlet[] outlet;
     public static void createFranchise(Franchise[] franchise) throws FileNotFoundException {
          Scanner console = new Scanner(System.in);
          int choice = -1;
++++++++++++++++++++++++++++++++++++
          Outlet outlet = new Outlet();
          Outlet.readFile(outlet.getOutlet());
++++++++++++++++++++++++++++++++++++
          boolean invalidChoice = true;
          while (invalidChoice) {
          System.out.println("\nCreating a New Franchise...");
          System.out.println(STARS);
          System.out.println("Please select an outlet from the list below");
          Outlet.displayUnassignedOutlets(outlet.getOutlet());
          choice = console.nextInt();
          if (choice < 0 || choice > 10) {
               System.out.println("Error! Please choose a single number between 1 and 10");
          else {
               invalidChoice = false;
          invalidChoice = true;
          while (invalidChoice) {
               System.out.println("Please enter the Phone Number for this Outlet");
               choice = console.nextInt();
               String phone = new String();
          phone = new Integer(choice).toString();
               if (phone.length() < 8 || phone.length() > 10) {
                    System.out.println("Error! Please enter 8 to 10 digits only");
               else {
+++++++++++++++++++++++++++++++++++++++
                    outlet[(choice - 1)].setPhoneNumber(choice);
+++++++++++++++++++++++++++++++++++++++
                    invalidChoice = false;

Hi Pete!
Thanks for your comments. I have included my full classes below with their respective driver modules. Hope this helps out a bit more using the code tags. Sorry, it was my first posting. Thanks for the heads up!
import java.util.*;
import java.io.*;
public class Outlet {
     public Outlet[] outlet;
     private String outletName;
     private int phoneNumber;
     private int category;
     private int operatingDays;
//     private Applicant chosenApplicant;
     static boolean SHOWDETAILS = false;
     static final String STARS = "****************************************";
     static final int MAXOUTLETS = 10;
     static final int DEFAULT = 99;
     public Outlet[] getOutlet() {
          return outlet;
     public String getOutletName() {
          return outletName;
     public int getPhoneNumber() {
          return phoneNumber;
     public int getCategory() {
          return category;
     public int getOperatingDays() {
          return operatingDays;
     public void setOutletName(String newOutletName) {
          outletName = newOutletName;
     public void setPhoneNumber(int newPhoneNumber) {
          phoneNumber = newPhoneNumber;
     public void setCategory(int newCategory) {
          category = newCategory;
     public void setOperatingDays(int newOperatingDays) {
          operatingDays = newOperatingDays;
     public Outlet() {
          outlet = new Outlet[10];
     public static void readFile(Outlet[] outlet) throws FileNotFoundException {
          Scanner inFile = new Scanner(new FileReader("outlets.txt"));
          int rowNo = 0;
          int i = 0;
          String outletValue;
          while (inFile.hasNext() && rowNo < MAXOUTLETS) {
               outlet[rowNo] = new Outlet();
               outletValue = inFile.nextLine();
               outlet[rowNo].setOutletName(outletValue.toUpperCase());
               //System.out.println(rowNo % 2);
          //     if (rowNo % 2 == 0) {
               outlet[rowNo].setPhoneNumber(DEFAULT);
               outlet[rowNo].setCategory(DEFAULT);
               outlet[rowNo].setOperatingDays(DEFAULT);
//               System.out.println("Outlet Name+++++++ " + rowNo + "\n" + outlet[rowNo].getOutlet());
               rowNo++;
     //          System.out.println(rowNo);
          if (SHOWDETAILS) {
               if (rowNo > 6) {
                    for (i = 0; i < rowNo; i++ ) {
                         System.out.println("\nOutlet Name+++++++ " + (i + 1) + "\t" +
                                   outlet.getOutletName());
          inFile.close();
     public static void displayAllOutlets(Outlet[] outlet) {
          int i = 0;
          System.out.println("Showing All Outlets");
          System.out.println(STARS);
          for (i = 0; i < MAXOUTLETS; i++ ) {
               System.out.println("\nOutlet Number: " + (i + 1) + "\t" +
                         outlet[i].getOutletName());
     public static void displayUnassignedOutlets(Outlet[] outlet) {
          int i = 0;
          System.out.println("Showing all unassigned Outlets");
          System.out.println(STARS);
          for (i = 0; i < MAXOUTLETS; i++ ) {
               if (outlet[i].getCategory() == DEFAULT) {
               System.out.println("\nOutlet Number: " + (i + 1) + "\t" +
                         outlet[i].getOutletName());
     public static void main(String[] args) throws FileNotFoundException {
          Outlet start = new Outlet();
          Outlet.readFile(start.getOutlet());
          Outlet.displayUnassignedOutlets(start.getOutlet());
================================
So in the below Franchise class, when I specify:
outlet[(choice - 1)].setPhoneNumber(choice);
I get the error that an array is required but the class Outlet is resolved. Any feedback is greatly appreciated!
import java.io.FileNotFoundException;
import java.io.PrintWriter;
import java.util.*;
public class Franchise {
     private Franchise[] franchise;
     public Outlet[] outlet;
     static final int MAXOUTLETS = 10;
     static final int DEFAULT = 99;
     static boolean SHOWDETAILS = false;
     static final String STARS = "****************************************";
     static final double REGHOTDOG = 2.50;
     static final double LARGEHOTDOG = 4;
     static final int SALESPERIOD = 28;
     static final int OPERATINGHOURS = 8;
     public Franchise[] getFranchise() {
          return franchise;
     public Franchise() {
     public static void createFranchise(Franchise[] franchise) throws FileNotFoundException {
          Scanner console = new Scanner(System.in);
          int choice = -1;
          //franchise[i] = new Franchise();
          Outlet outlet = new Outlet();
          //outlet[i] = new Franchise();
          Outlet[] myOutlet = new Outlet[10];
          Outlet.readFile(outlet.getOutlet());
          boolean invalidChoice = true;
          while (invalidChoice) {
          System.out.println("\nCreating a New Franchise...");
          System.out.println(STARS);
          System.out.println("Please select an outlet from the list below");
          Outlet.displayUnassignedOutlets(outlet.getOutlet());
          choice = console.nextInt();
          if (choice < 0 || choice > 10) {
               System.out.println("Error! Please choose a single number between 1 and 10");
          else {
               invalidChoice = false;
          //System.out.println(j);
          invalidChoice = true;
          while (invalidChoice) {
               System.out.println("Please enter the Phone Number for this Outlet");
               choice = console.nextInt();
               String phone = new String();
              phone = new Integer(choice).toString();
               if (phone.length() < 8 || phone.length() > 10) {
                    System.out.println("Error! Please enter 8 to 10 digits only");
               else {
                    outlet[(choice - 1)].setPhoneNumber(choice);
                    invalidChoice = false;
          invalidChoice = true;
          while (invalidChoice) {
               System.out.println("Please enter the category number for this Outlet");
               choice = console.nextInt();
               if (choice < 1 || choice > 4) {
                    System.out.println("Error! Please choose a single number between 1 and 4");
               else {
                    outlet.setCategory(choice);
                    invalidChoice = false;
          invalidChoice = true;
          while (invalidChoice) {
               System.out.println("Please enter the Operating Days for this Outlet");
               choice = console.nextInt();
               if (choice < 5 || choice > 7) {
                    System.out.println("Error! Please choose a single number between 5 and 7");
               else {
                    outlet.setOperatingDays(choice);
                    invalidChoice = false;
//          Applicant chosenApplicant = new Applicant();
     //     Applicant.readFile(chosenApplicant.getApplicant());
          //Applicant.checkCriteria(chosenApplicant.getApplicant());
     //     System.out.println("This Franchise has been assigned to : " +
          //          chosenApplicant.displayOneEligibleApplicant());
          Outlet.displayUnassignedOutlets(outlet.getOutlet());
     public static void main(String[] args) throws FileNotFoundException {
          Franchise start = new Franchise();
          Franchise.testing(start.getFranchise());
          //Franchise.createFranchise(start.getFranchise());
          //Franchise.displaySalesForcast();
          //Franchise.displayAllFranchises(start.getOutlet());

Using a For Loop Index for Array Element Number?

Hi. Thanks in advance for the help. I can't seem to find what I want to do here using the search function... probably because I don't know how to frame the question appropriately. Ignore the title to this post cause it's probably wrong vocabulary for what I want to do.
Here's the situation:
I have a 2D array where the first column is the X data and each subsequent column is Y data (call it Y1...Yn). The n-value varies from run to run (some runs have 4 columns of data, some have 20), but that is easily gathered when reading the data file. I need to perform a number of operations on each set of data, the least of which is smoothing the data and graphing it, so I'm limiting my discussion to these 2 operations.
What I want is a for loop structure where the indexing of the loop tracks the Y1...Yn columns, grabs each column for the iteration, performs the relevant analysis, and spits out the result, but in a stackable manner. Thus the title; I want to use the for loop's index to mark the array element for building a new array.
See the image attached. A 2D array of 9 columns (X, Y1...Y8) is analyzed such that each data set, (X, Y1), (X, Y2)...(X, Y8) is bundled, graphed, run through a B-spline Fit, of which is also graphed. I need to replace this with something that looks like the for loop structure shown.
I just don't know how to get those two data bundles [(X, Yi) and it's smoothed pair] out of the for loop in a stacked set from every iteration of the for loop.
Again the title, I think I want to build a new array where i use the index of the for loop to control the entries of the new array. But I can't see how to do that.
Any help would be appreciated.
Attachments:
NeedForLoopForThis.PNG ‏30 KB

Hello H.R. Dunham, and welcome to the forum!
It seems that you may be looking for Auto-Indexing, a basic feature of loops in LabVIEW. You'll need to transpose your array before wiring it into the for loop, as elements are auto-indexed by row before column, but at that point you should be able to operate on each column and output an array of n cluster elements corresponding to your input columns. Auto-indexing tunnels look like brackets to indicate each element will be indexed automatically- this should be the default when wiring an array into a for loop or when wiring anything out of a for loop.
As for how to build your pairs, I suggest removing the X column and creating a "starter" cluster containing your X data and placeholder Y data before entering your "Y" processing loop. Use the bundle by name function in the for loop to insert your processed column data into the cluster and auto-index the cluster output. Flow would be something like this:
1) Gather data
2) Split X and Y using standard array operations
3) Create "template" cluster with shared X data
4) Pass template cluster and Y-column array into an auto-indexed for loop.
5) Insert processed Y data into cluster inside loop.
6) Auto-index cluster data out of loop.
This tutorial is probably also a good place to get started:
Getting Started with NI LabVIEW Module 3: Loops
http://www.ni.com/white-paper/7528/en/
Hope that helps!
Regards,
Tom L.

Select array elements dynamically

Hello ...
I am trying to write a program where one can select the array elements dynamically from the front panel when the VI is in run mode.
So far, IC_OpenDevice.vi gives me the various Video formats [It is a 1D array], right now I assume the last but one among this array as an example. But, I would like to design the program in such a way that the user can select any Video Format from the front panel. How do I achieve that ??
Block Diagram :
Front Panel:
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]
Solved!
Go to Solution.

I tried following the same method on my program.
However, I get the Error -2147352567 ... Below is the changes I made to my program ...
Abhilash S Nair
Research Assistant @ Photonic Devices and Systems lab
[ LabView professional Development System - Version 11.0 - 32-bit ]
LabView Gear:
1. NI PXI-7951R & NI 5761
2. The Imaging Source USB 3.0 monochrome camera with trigger : DMK 23UM021
OPERATING SYSTEM - [ MS windows 7 Home Premium 64-bit SP-1 ]
CPU - [Intel Core i7-2600 CPU @ 3.40Ghz ]
MEMORY - [ 16.0 GB RAM ]
GPU - [ NVIDIA GeForce GT 530 ]
Attachments:
Image_Capture_Dev5.vi ‏25 KB

How do I programmatically modify array element sizes?

Hi All,
I have a quick question about modifying the size of array elements. Hopefully someone can help, because I am at a dead end!
I am logging some intensities from a Fibre Array using a camera. For calibration of the system, I acquire an image from the camera, click points on the image to divide it into areas of interest. I overlay my image with a grid showing the regions of interst - for example a 4x6 array. I then have to select the fibres - or ROIs - I want to log from.
I have a cluster type-def ( a number and a boolean) to specify the fibre number and to turn logging from that fibre on/off. I overlay an (transparent) array of this typedef over my image to correspond with the regions of interest. So here's my problem - I want to modify the dimensions of the array so each control matches my ROI. I can resize the elements by rightclicking on the elements on the frontpanel, but can't find a way to do it programmatically. The Array Property Node>>Array Element>>Bounds won't 'change to write'...thats the first thing I tried.
Its really only important that the elements align with my ROIs - so programmatically adding in gaps/spacings would also work for me...but again I can't figure out how to do this! I've attached a screenshot of part of my image with array overlaid to show you all exactly what my problem is.
Thanks in advance for you help,
Dave
PS I am running Labview 8.6 without the vision add on.
Solved!
Go to Solution.
Attachments:
Array_Overlay.png ‏419 KB

Here's my cheat (and cheap?) way If you want to get fancy and center the numeric and boolean indicators, you could add spacers on the north and west sides, too.
Attachments:
ClusterSpacer.vi ‏13 KB

How can I display all results of a array element in a TS2.0 NumericArrayMeasurement in a single report line?

TestStand2.0 generates for each result property ( data, limits, status...) of each array element in a NumericArrayTest an extra line in the test report.
How can I change this to display all result properties of one array element in a single line?
How can I reduce the spaces between the property name and its value in the report?
How can I delete the message: "Measurement[x]" and display only the Measurement Alias (named in the Edit Limits menu)?
This means I like to change my report from:
Measurement[0] (ADC1):
Data: 5000
Status: Passed
Measurement[1] (AD
C2):
To:
ADC1: Data: 5000 Status: Passed
ADC2: ...

Hi,
What you can do, is use the Override Callbacks for Modify the Report that is Generated.
Also you can also change the report sequence 'reportgen_txt.seq' to achieve the desired affect. If you go for modifying the report sequence then copy this to the User folder and then make your changes.
In the Resources Library you can find simple examples were the report has been modified by either using the Override Callbacks or by modifying the actual sequence.
One other item in the Report Options you will have to set the 'Select a Report Generator for Producing the Report Body' control to use the Sequence instead of the DLL.
Hope this helps
Ray Farmer
Regards
Ray Farmer

How to use XSLT for mapping feild names one by one to array element

I have a XSLT case to map all the attributes feild name(not value) which has no child to the target, which is array loop.
I give an sample below.
source:
<Items xmlns="http://www.example.org/sample">
<SourceSystem>SourceSystem2573</SourceSystem>
<TimeStamp>2010-01-17T20:54:08.234</TimeStamp>
<Item>
<ID>2574</ID>
<Type>2575</Type>
<Name>2576</Name>
</Item>
</Items>
source XSD like:
     <element name="Items" type="tns:ItemsType"></element>
     <complexType name="ItemsType">
          <sequence>
               <element name="SourceSystem" type="string" maxOccurs="1"
                    minOccurs="1">
               </element>
               <element name="TimeStamp" type="dateTime" maxOccurs="1"
                    minOccurs="1">
               </element>
               <element name="Item" type="tns:ItemType"
                    maxOccurs="unbounded" minOccurs="1">
               </element>
</sequence>
     </complexType>
<complexType name="ItemType">
          <sequence>
               <element name="ID" type="string" maxOccurs="1"
                    minOccurs="1">
               </element>
               <element name="Type" type="string" maxOccurs="1"
                    minOccurs="1">
               </element>
<element name="Name" type="string" maxOccurs="1"
                    minOccurs="1">
               </element>
</sequence>
     </complexType>
target need to be like:
<ns1:AttributesCollection>
<ns1:Attributes>
<ns1:fieldname>SourceSystem</ns1:fieldname>
</ns1:Attributes>
<ns1:Attributes>
<ns1:fieldname>TimeStamp</ns1:fieldname>
</ns1:Attributes>
<ns1:Attributes>
<ns1:fieldname>ID</ns1:fieldname>
</ns1:Attributes>
<ns1:Attributes>
<ns1:fieldname>Type</ns1:fieldname>
</ns1:Attributes>
<ns1:Attributes>
<ns1:fieldname>Name</ns1:fieldname>
</ns1:Attributes>
</ns1:AttributesCollection>
target XSD:
<xs:element name="AttributesCollection" type="AttributesCollection"/>
<xs:complexType name="AttributesCollection">
<xs:sequence>
<xs:element name="Attributes" type="Attributes" minOccurs="0" maxOccurs="unbounded"/>
</xs:sequence>
</xs:complexType>
<xs:complexType name="Attributes">
<xs:sequence>
<xs:element name="fieldname" minOccurs="0">
<xs:simpleType>
<xs:restriction base="xs:string">
<xs:maxLength value="100"/>
</xs:restriction>
</xs:simpleType>
</xs:element>
</xs:sequence>
</xs:complexType>
I know we can use local-name() to get the tag/field name,
but I have not idea how to get these leaf field names one by one and then mapping to every array elements.
I tried whole day but no successful
Does anyone have some idea?
Thanks very much!
Keith
Edited by: user1065212 on 17-Jan-2010 22:50
Edited by: user1065212 on 17-Jan-2010 22:53
Edited by: user1065212 on 17-Jan-2010 22:59

can you paste source xsd and the correct xml output, the current one isn't really valid
<ID>2574</TotalNumOfItems>

Allocate array elements one at a time?

Is there a way to allocate array elements one at a time?
The following code will crash because the minimumLogIndices array is not allocated.
// get all indices where cArray[i] > minimumLog
int[] minimumLogIndices = null;
for (int i=0; i < columns; i++)
if ((cArray[i] > minimumLog))
minimumLogIndices[i] = i;
}I would like a statement like:
minimumLogIndices[i] = new(i);but this is not allowed, of course.
If I use ArrayList, then the elements can be added one at a time, but I cannot use int.
null

int[] minimumLogIndices = new int[columns];As described here:
http://java.sun.com/docs/books/tutorial/java/nutsandbolts/arrays.html
[Edit] The array will, however, have "holes" in it when cArray[i] <= minimumLog, but that's inevitable if you are using an array.

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

Problem in assigning value to an array element

hi all
in the following prog i am not able to assign the value to the array element
i am not getting why it is giving me error
//my program is as follows
public class ArrayTest
     static int [] intArray = new int[5];
     static int [] intArray1 = new int[1];
     intArray1[0] = 5; // this line gives error
     static char [] charArray = new char[5];
     public static void main(String args[])
          System.out.println(charArray);
          intArray1 = intArray;
}thanx in advance as usual

The problem is that you try to execute code outside a method. This can be only done in form of a variable declaration or as a static initilization block which will be executed once when the class is loaded:public class ArrayTest
     static int [] intArray = new int[5];
     static int [] intArray1 = new int[1];
     static char [] charArray = new char[5];
     static {
          intArray[0] = 5;
     public static void main(String args[])
          System.out.println(charArray);
          intArray1 = intArray;
}

Atomic operation on array elements

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