Concatenate clusters to array with enums

Hi I am trying to concatenate three 1D arrays filled with an i32 and an enum.
When i look at my concatenated array i lose my enum information... It makes 0,1,2,3,4 etc... instead of the channel names??
Does anyone have a solution for this?
Best regards,
Thijs
Solved!
Go to Solution.

How exactly did you 'look' at the concatenated array? If you use a numeric indicator instead of enumerated, the VI will execute, but you will lose the enum names.
However, if you probe the wire, and/or Right Click > Create Indicator... you should not encounter the problem, in which case the problem must lie somewhere else.

Similar Messages

NXT Flatten to String Not Working with Clusters and Arrays

Hello,
My name is Joshua and I am from the FIRST Tech Challenge Team 4318, Green Machine. We are trying to write a program that will write to a configuration file and read it back. The idea is that we will be able to write to a config file from our computer that will be read by our autonomous program when it runs. This will define what the autonomous program does.
The easiest way to do this seems to be flattening a data structure to a string, saving it to a file, and then reading back and unflattening it. The issue is that the flatten to string and unflatten from string VIs don't seem to work with arrays and clusters on the NXT. It does work when running on the computer. We've tried arrays, clusters, clusters in arrays and arrays in clusters, none seem to work. Thinking it was something to do with reading the string from a file, we tried bypassing the file functionality, still not working. It does work with basic data types though, such as strings and numbers.
No error is thrown from what we can tell. All you get is a blank data structure out of the unflatten VI.
The program attached is a test program I've been working on to get this functionality to work. It will display the hex content of what is going into the file, coming out of the file, and then the resulting data from the unflatten string, as well as any errors that have been thrown. The data type we are using simulates what we would like to store. There is also a file length in and out counter. The out file is a little larger because the NXT write file VI adds a new line character on to the end (thus the use of the strip white space VI). This character was corrupting even basic data types saved to file.
I would like to know if there is a problem with what we are doing, or if it is simply not possible to flatten arrays on the NXT. Please ask if you have any questions about the code. Thank you in advanced!
Joshua
Attachments:
ReadableTest.vi ‏20 KB

Hi jfireball,
This is a very interesting situation. Take a look at what kbbersch said. I also urge you to post in the FTC Forums. You posted your question to the general LabVIEW forums, but by posting to the FTC Forums, you will have access to others that are using the NXT hardware.
David B.
Applications Engineer
National Instruments

What's the deal with enums?

Hello,
I'm trying to familiarise myself with the new Java features that project Tiger (Java 1.5) will introduce. I come from a C++ programming background. I very briefly studied enums whilst I learned C++ and never used them in my programs, so I was, quite frankly, relieved when I learned that Java didn't support them.
But now it does.
I'm wondering, from a software design and engineering perspective, what benefit enums will add to the Java language and software engineering in general. I have read some pleas and arguments for enums. As I understand those arguments, proponents feel that minor ledgibility improvements to switch statements (which some OO programmers don't use on the basis that it weakens the object-orientedness through its goto-esque break statements) necessitate the addition of a whole other structure.
Out of curiosity, wouldn't it be more advantageous for Sun to put their efforts into supporting constant strings in switches in addition to primitive data types if people are so concerned with clarity?
I fail to understand what enums will do that constant string arrays or constant values cannot. I would like to think that Sun wouldn't add C++ features unless if there was a reason to do so, so I believe that there are good reasons to introduce this feature.
Please help clarify this confusion.
Thank you!

Comments on the previous posting inline. Note: I'll go off on a few tangents, but try to always return to the issue of enums. The fact that I go off on tangents (related initially to an enum type example) should show that enums help eliminate numerous problems.
Fair enough, but wouldn't this accomplish the same thing in
a slightly wordier wayPretty much. But you still have the validation code in there yourself:
currentDirection = ( direction > 0 && direction < 5 ? direction : 0 );People can still accidentally enter an invalid value, and it won't get caught by the compiler. So, I could call set(Compass.WEST) and hope/expect that is equivalent to set(Direction.LEFT). This will only occur if both Compass.WEST and Direction.LEFT are the same int value. If they are not, then we are in trouble. Worse, still if Compass.WEST and Direction.RIGHT are the same value, the code will compile, and run without any illegal value flagging, but our traveller will go off in the wrong direction.
Error handling tangent: Given the implementation, the error handling is not performed in set, rather the illegal value is captured as a zero, which must be dealt with at a later time - say in a switch statement that calls get. This is not a good idea - it increases the "distance" between the error occuring (bad call to set) and the error being detected (if xInt != 0). The larger the distance, the harder debugging is. If you throw an exception in set the bug is immediately flagged. With enums, none of this should be necessary.
Implementation tangent: set, get and currentDirection are static. This is not a good idea - it only allows one direction. If you have multiple travellers, each would have a Direction object, but (sticking with constants) UP, etc. would still be static.
I keep the switch statement in my enum workaround, but I believe that
the second reply suggested that enum could altogether eliminate the
use for switch statements. How exactly would it do that?enum in its simplest form would not remove switch. However, using an extension of the type-safe enum idiom (i.e. the current Java approach to enums), you can embed direction specific logic in each of the "enum" members. If I understand the enum-spec correcly, this will also be possible with the Java 1.5 enum language facility.
So, for an example, sticking with the domain: Consider a class Location, with x and y elements, and a Direction. The non-OO, non-enum approach would be as follows:
class Location {
    int x,y;
    void move (final int direction) {
        switch (direction) {
            case UP:
                --y;
                break;
            case DOWN:
                ++y;
                break;
            case LEFT;
                --x;
                break;
            case RIGHT:
                ++x;
                break;
            default;
                throw new RuntimeException("Invalid direction " + direction);
class Direction {
    public static final int UP = 1;
    public static final int DOWN = 2;
    public static final int LEFT = 3;
    public static final int RIGHT = 4;
}Note that I've deliberately been loose with my visibility. All logic is in Location, and Direction is dumb. If we go with a type safe-enum idiom, we get:
class Location {
    int x,y;
    void move (final Direction direction) {
        if (direction == Direction.UP) {
            --y;
        } else if (direction == Direction.DOWN) {
            ++y;
        } else if (direction == Direction.LEFT) {
            --x;
        } else if (direction == Direction.RIGHT) {
            ++x;
        } else { // direction is null
            throw new NullPointerException("null direction");
class Direction {
    public static final Direction UP = new Direction();
    public static final Direction DOWN = new Direction();
    public static final Direction LEFT = new Direction();
    public static final Direction RIGHT = new Direction();
    private Direction () {} // the ctor is private to limit instances
}This code is a rewrite of the int approach, but is "type-safe". We've moved from switch to if as we can't switch on object references. Note: there is still error handling code, as you're not "null-safe" (I don't know what the Java 1.5 spec says about this)
Little else has changed - the responsibilities are still the same. We can address this by going OO, which removes the if (formerly a switch) statement, but does couple the classes.
class Location {
    int x,y;
    void move (final Direction direction) {
        direction.move(this);
class Direction {
    private final int xOffset, yOffset;
    private Direction (final int xOffset, final int yOffset) {
        this.xOffset = xOffset;
        this.yOffset = yOffset;
    public static final Direction UP = new Direction(0,1);
    public static final Direction DOWN = new Direction(0,-1);
    public static final Direction LEFT = new Direction(-1,0);
    public static final Direction RIGHT = new Direction(1,0);
    void move(final Location location) {
        location.x += xOffset;
        location.y += yOffset;
}This removes any conditional logic, embedding (constructor parameterised) logic within Direction. It also eliminates the "null-safe" check, as direction.move(this) will throw an NPE if a null is passed.
Also, I've read some things saying that enum reduces 'boilerplate'
code. What exactly does that and 'boilerplate' mean?The Direction class is an example of the type-safe enum approach currently used in Java. It has been enhanced with logic for movement. Even if I dropped this logic, there is still functionality worth adding to the Direction class - a toString method that returns one of "UP", "DOWN", etc (shown next); a way to serialize the object and retain reference equality - you have to write a readResolve method (not shown).
class Direction {
    private final String name;
    private Direction (final String name) {
        this.name = name;
    public static final Direction UP = new Direction("UP");
    public static final Direction DOWN = new Direction("DOWN");
    public static final Direction LEFT = new Direction("LEFT");
    public static final Direction RIGHT = new Direction("RIGHT");
    public String toString() {
        return name;
}Once you've written this code for one type-safe enum, you've written them for them all. You copy-cut-paste, and rename the class/elements. All this code is predictable. It is "boiler plate". Now, if you gave me a compiler that generated all this code for me, when I present it with
enum Direction {UP, DOWN, LEFT, RIGHT}; then I've got something that reduces my boiler plate code to zip.... Enter the Java 1.5 compiler.

How do you create array of enums for transitions in a state machine?

Hello,
I am trying to build a state machine, but, I am struggling with understanding the methods for determining which state to transition to next. In other words, I have several states, but, I don't want to go in any particular sequence. If I have states numbered 1 through 10, I want to be able to go 1-4-2-5-6-2-6-1-10 etc. in no particular order. I want the transition to the next state (and actions) to be determined by the streaming data, which can be random and require access to any of my 10 states at any time and in any sequence.
I saw this picture on the "Application Design Patterns: State Machines" white paper, but, it leaves out some important details. How does one create the structure in BLUE shown in 3C? When I try to create this array of enums, all of them are the same. I am not able to make a list of different enum values. In other words, when I type in "2", then, all the values in the array display as "2."
There is a nice, simple video example of a state machine for dispensing soda for $0.15, however, this state machine moves in a single sequence, from 5 cents, to 10 cents to dispense; it does NOT illustrate how to select a state "out of order." I need to understand how a state machine can move from "5 cents" state to dispense directly, with the addition of 10 cents to the "5 cents" state.
Can anyone suggest a really good tutorial on how to make the selector work in a state machine? I have been reading some of the available material on ni.com, but, I can't find a good detailed explanation of how to do it. I remain confused.
Or, can you just explain how they created the BLUE array in the attached picture? Maybe I can figure it out from there.
Thanks,
Dave
Solved!
Go to Solution.
Attachments:
next state.jpg ‏75 KB

Hi Kathryn,
Yes, this is EXACTLY what I want to accomplish...
So it would basically run:
State 1
Read input
Determine next state (say 3)
State 3
Read input
Determine next state
State
Read input
Determine next state
And so on...
But, I am quite new to programming Labview state machines, and can't figure out how to even start when the sequence of states is random instead of fixed!!! I can do 1,2,3,4, like the vending machine VI example, but, not 1,3,2,2,2,5,2,1 etc. based on external input. Is there some simple example case I can study? I can't believe I am inventing this for the first time.
"select the state to run"
But, HOW do I do this??????? This is exactly the question I am asking...how is this done? Please see the attached 3-state system....how do I hook this up???? I am totally lost here...can you help me understand how to wire this thing?? In this simpe RED/GREEN/BLUE case, my input is just the number a user would input on the front panel.... Apparently, there are two files necessary... a vi and .ctl??? What is .ctl?
Thanks,
Dave
Attachments:
forum nov 12 red green blue.vi ‏7 KB
forum nov 12 red green blue.ctl ‏5 KB

Possible bug: Saving array with extended and double precision to spreadsheet

If one concatenates a double precision array and an extended precision array with the "build array" vi and then saves using "Write to Spreadsheet File" vi any digits to the right of the decimal place are set to zero in the saved file. This happens regardless of the format signifier input (e.g. %.10f) to the "Write to Spreadsheet File" vi.
I am on Vista Ultimate 32 bit and labview 9.0
This is a possible bug that is easily circumvented by converting to one type before combining arrar to a spreadsheet. Nonetheless, it is a bug and it cost me some time.
Solved!
Go to Solution.
Attachments:
Spreadsheet save bug.vi ‏9 KB

Hi JL,
no, it's not a bug - it's a feature
Well, if you would look more closely you would recognize the "Save to Spreadsheet" as polymorphic VI. As this polymorphic VI doesn't support EXT numbers internally (it only supports DBL, I64 and String) LabVIEW chooses the instance with most accuracy: I64 (I64 has 64 bits precision, DBL only 53...). So your options are:
- set the instance to use as DBL (by right-click and "Select type...")
- make a copy of this VI, save it with a different name and make it support EXT numbers (don't rework the polymorphic VI as you would break compatibility with other LV installations or future revisions)
And yes, those coercion dots always signal some conversions - you should atleast check what's going on there...
Message Edited by GerdW on 05-21-2010 10:01 PM
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

How concatenate date and array to write in excel?

Hello
I have a problem to concatenate a date array and numeric array. can you help me?
I want save Measurement of a sensor with save time in an excel (row 1 column1 save date and row 1 coulmn : save sensor data). but I cant save these two value seperatly(my clocks cant do it). now, I want concatenate them at first and then save them. is it possible?
Best Regards
Solved!
Go to Solution.
Attachments:
concatenate.jpg ‏82 KB

Try the attached. You'll understand it as soon as you see it. If not, shout.
Attachments:
write_to_file.vi ‏8 KB

EJB QL: Passing array of enum to SELECT * WHERE a IN () clause

Hello,
I am trying to pass an array of enum to EJB QL as followed:
em.createQuery("FROM OrderInfo o WHERE o.ordStatus IN (:ordStatus)")
.setParameter("ordStatus", ordStatsStr)Note that o.ordStatus is of type enum OrderStatus.
I've tried to set "ordStatus" as String (i.e. 'OPEN', 'CLOSED'), as well as an array of enum but EJB QL would not parse them (perhaps for a good reason). EJB QL (I use JBoss + Hibernate) threw the following exception (or similar depending on whether I passed in an array of enum or a String):
org.hibernate.TypeMismatchException: named parameter [ordStatus] not of expected type;
expected = class ....OrderStatus; but was =java.lang.StringCan someone show me the way to set the IN clause with an array of enum?
Thanks

I suppose that your enum declaration is like
public enum OrderStatus{
OPEN,
CLOSED
The exception remarks that the valid type must be OrderStatus. I think that you must change your sentence by
em.createQuery("FROM OrderInfo o WHERE o.ordStatus IN (:ordStatus)")
.setParameter("ordStatus", OrderStatus.OPEN);
On the other hand, for the array option I think that you must use setParameterList like this
OrderStatus options[] = new OrderStatus[2];
options[0] = OrderStatus.OPEN;
options[1] = OrderStatus.CLOSED;
em.createQuery("FROM OrderInfo o WHERE o.ordStatus IN (:ordStatus)")
.setParameterList("ordStatus", options);
I hope it helps you
hayken.

How do I cerate an array with a set of numbers lets say 1 through 12 random order but no repeating.

How do I cerate an
array with a set of numbers lets say 1 through 12 random order but no
repeating.
I know this should be easy but my brain wont work
right now
Solved!
Go to Solution.

OK, here's the handmade version.
It is useful to know that arrays of clusters are sorted by the cluster order of the elements. Simply bundle random numbers with numbers 1-12 in a loop, create an array at the output tunnel, sort the array by the random number, and extract the number array. It will be shuffled.
Message Edited by altenbach on 06-04-2007 09:20 PM
LabVIEW Champion . Do more with less code and in less time .
Attachments:
shuffleArray.png ‏5 KB

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;
}

Auto-indexing is slow for arrays with 1 dimensions

Hi,
I was looking at the performance of operations on all individual elements in 3D arrays, especially the difference between auto-indexing (left image) and manual-indexing (right image, calling "Index array" and "Replace array subset" in the innermost loop). I'm a bit puzzled by the results and post it here for discussion and hopefully somebody's benefit in the future.
Left: auto-indexing; right: manual-indexing
In the tests I added a different random number to all individual elements in a 3D array. I found that auto-indexing is 1.2 to 1.5 times slower than manual-indexing. I also found that the performance of auto-indexing is much more dependent on the size the dimensions: an array with 1000x200x40 elements is 20% slower than an array with 1000x40x200 elements. For manual-indexing there is hardly any difference. The detailed results can be found at the end of this post.
I was under the impression that auto-indexing was the preferred method for this kind of operation: it achieves exactly the same result and it is much clearer in the block diagram. I also expected that auto-indexing would have been optimized in LabView, but the the tests show this is clearly not the case.
What is auto-indexing doing?
With two tests I looked at how auto-index works.
First, I looked if auto-indexing reorganizes the data in an inefficient way. To do this I made a method "fake-auto-indexing" which calls "Array subset" and "Reshape array" (or "Index array" for a 1D-array) when it enters _every_ loop and calls "Replace array subset" when exiting _every_ loop (as opposed to manual-indexing, where I do this only in the inner loop). I replicated this in a test (calling it fake-auto-indexing) and found that the performance is very similar to auto-indexing, especially looking at the trend for the different array lengths.
Fake-auto-indexing
Second, I looked if Locality of reference (how the 3D array is stored in memory and how efficiently you can iterate over that) may be an issue. Auto-indexing loops over pages-rows-columns (i.e. pages in the outer for-loop, rows in the middle for-loop, columns in the inner for-loop). This can't be changed for auto-indexing, but I did change it for manual and fake-indexing. The performance of manual-indexing is now similar to auto-indexing, except for two cases that I can't explain. Fake-auto-indexing performs way worse in all cases.
It seems that the performance problem with auto-indexing is due to inefficient data organization.
Other tests
I did the same tests for 1D and 2D arrays. For 1D arrays the three methods perform identical. For 2D arrays auto-indexing is 15% slower than manual-indexing, while fake-auto-indexing is 8% slower than manual-indexing. I find it interesting that auto-indexing is the slowest of the three methods.
Finally, I tested the performance of operating on entire columns (instead of every single element) of a 3D array. In all cases it is a lot faster than iterating over individual elements. Auto-indexing is more than 1.8 to 3.4 times slower than manual-indexing, while fake-auto-indexing is about 1.5 to 2.7 times slower. Because of the number of iterations that has to be done, the effect of the size of the column is important: an array with 1000x200x40 elements is in all cases much slower than an array with 1000x40x200 elements.
Discussion & conclusions
In all the cases I tested, auto-indexing is significantly slower than manual-indexing. Because auto-indexing is the standard way of indexing arrays in LabView I expected the method to be highly optimized. Judging by the tests I did, that is not the case. I find this puzzling.
Does anybody know any best practices when it comes to working with >1D arrays? It seems there is a lack of documentation about the performance, surprising given the significant differences I found.
It is of course possible that I made mistakes. I tried to keep the code as straightforward as possible to minimize that risk. Still, I hope somebody can double-check the work I did.
Results
I ran the tests on a computer with a i5-4570 @ 3.20 GHz processor (4 cores, but only 1 is used), 8 GB RAM running Windows 7 64-bit and LabView 2013 32-bit. The tests were averaged 10 times. The results are in milliseconds.
3D-arrays, iterate pages-rows-columns
pages x rows x cols : auto    manual fake
   40 x 200 x 1000 : 268.9   202.0   268.8
   40 x 1000 x 200 : 276.9   204.1   263.8
200 x   40 x 1000 : 264.6   202.8   260.6
200 x 1000 x   40 : 306.9   205.0   300.0
1000 x   40 x 200 : 253.7   203.1   259.3
1000 x 200 x   40 : 307.2   206.2   288.5
100 x 100 x 100 : 36.2    25.7    33.9
3D-arrays, iterate columns-rows-pages
pages x rows x cols : manual fake
   40 x 200 x 1000 : 277.6   457
   40 x 1000 x 200 : 291.6   461.5
200 x   40 x 1000 : 277.4   431.9
200 x 1000 x   40 : 452.5   572.1
1000 x   40 x 200 : 298.1   460.4
1000 x 200 x   40 : 460.5   583.8
100 x 100 x 100 : 31.7    51.9
2D-arrays, iterate rows-columns
rows x cols : auto     manual   fake
200 x 20000 : 123.5    106.1    113.2
20000 x   200 : 119.5    106.1    115.0
10000 x 10000 : 3080.25 2659.65 2835.1
1D-arrays, iterate over columns
cols   : auto manual fake
500000 : 11.5 11.8    11.6
3D-arrays, iterate pages-rows, operate on columns
pages x rows x cols : auto    manual fake
   40 x 200 x 1000 : 83.9   23.3     62.9
   40 x 1000 x 200 : 89.6   31.9     69.0
200 x   40 x 1000 : 74.3   27.6     62.2
200 x 1000 x   40 : 135.6   76.2    107.1
1000 x   40 x 200 : 75.3   31.2     68.6
1000 x 200 x   40 : 133.6   71.7    108.7
100 x 100 x 100 : 13.0    5.4      9.9
VI's
I attached the VI's I used for testing. "ND_add_random_number.vi" (where N is 1, 2 or 3) is where all the action happens, taking a selector with a method and an array with the N dimensions as input. It returns the result and time in milliseconds. Using "ND_add_random_number_automated_test.vi" I run this for a few different situations (auto/manual/fake-indexing, interchanging the dimensions). The VI's starting with "3D_locality_" are used for the locality tests. The VI's starting with "3D_norows_" are used for the iterations over pages and columns only.
Attachments:
3D_arrays_2.zip ‏222 KB

Robert,
the copy-thing is not specific for auto-indexing. It is common for all tunnels. A tunnel is first of all a unique data space.
This sounds hard, but there is an optimization in the compiler trying to reduce the number of copies the VI will create. This optimization is called "in-placeness".
The in-placeness algorithm checks, if the wire passing data to the is connected to anything else ("branch"). If there is no other connection then the tunnel, chance is high that the tunnel won't create an additional copy.
Speaking of loops, tunnels always copies. The in-placeness algorithm cannot opt that out.
You can do a small test to elaborate on this: Simply wire "0" (or anything less than the array sizy of the input array) to the 'N' terminal.......
Norbert
PS: Auto-indexing is perfect for a "by element" operation of analysis without modification of the element in the array. If you want to modify values, use shift registers and Replace Array Subset.
CEO: What exactly is stopping us from doing this?
Expert: Geometry
Marketing Manager: Just ignore it.

Unable to plot 1-D array with a cluster of 2 elements on an XY graph

I'm Unable to plot a 1-D array with a cluster of 2 elements on an XY graph. The data appears at the input to the graph but nothing is plotted. I'm trying to plot a line connecting each point generated.
Solved!
Go to Solution.
Attachments:
TEST11.vi ‏13 KB

Chuck,
0. Do not post VIs with infinite loops! Change the True constant to a control. One of the regular participants on these Forums has commented that using the Abort button to stop a VI is like using a tree to stop a car. It works, but may have undesired consequences!
1. Use a shift register on the For loop also.
2. Inserting into an empty array leaves you with an empty array. Initialize the array outside the loop to a size greater or equal to the maximum size you will be using. Then use Replace Array Subest inside the loop.
3. Just make an array of the cluster of points. No need for the extra cluster.
Lynn
Attachments:
TEST11.2.vi ‏11 KB

I have read 118 files (from a directory) each with 2088 data and put them into a 2 D array with 2cols and 246384row, I want to have aeach file on a separate columns with 2088 rows

I have read 118 files from a directory using the list.vi. Each file has 2 cols with 2088rows. Now I have the data in a 2 D array with 2cols and 246384rows (118files * 2088rows). However I want to put each file in the same array but each file in separate columns. then I would have 236 columns (2cols for each of the 118 files) by 2088 rows. thank you very much in advance.

Hiya,
here's a couple of .vi's that might help out. I've taken a minimum manipulation approach by using replace array subset, and I'm not bothering to strip out the 1D array before inserting it. Instead I flip the array of filenames, and from this fill in the end 2-D array from the right, overwriting the column that will eventually become the "X" data values (same for each file) and appear on the right.
The second .vi is a sub.vi I posted elsewhere on the discussion group to get the number of lines in a file. If you're sure that you know the number of data points is always going to be 2088, then replace this sub vi with a constant to speed up the program. (by about 2 seconds!)
I've also updated the .vi to work as a sub.vi if you wa
nt it to, complete with error handling.
Hope this helps.
S.
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Attachments:
read_files_updated.vi ‏81 KB
Num_Lines_in_File.vi ‏62 KB

Populating a javascript array with datatable data

I want to populate a javascript array with datatable data.
How do I do this?
I want the javascript array to be populated as the datatable is displayed.
Doing this way doesn't work.
<h:dataTable value="#{pmManager.profiles}" var="pmProfile" binding="#{pmManagerUiBean.uiTable}" ">
<script>
allProfilenames[index]='#{pmProfile.profileName}';
          alert("index ="+index);
          alert("...1"+allProfilenames[0]);
          alert("...2"+allProfileRes[0]);
          index++;
</script>
<h:dataTable>

In Javascript do something like this:
document.getElementById('form1:dec_param');
where form1:dec_param is the id of the component on the page source (html)

How to build a array with collected data

Hi,
I have collected data from serial port with VISA. Now I want to build a array with 100 date points. Should I connect VISA Read with Build Array directly? How to do it?
PS: All of them are in a While Structure.
Thank you!

An inefficient way to create the array is to use the build array and a shift register as shown below. It's more effecient in terms of memory management to create the array and then use the replace array subset as shown in the other image. Of course, if you don't need the array inside the loop, just wire the value out of the while loop and on the exit tunnel, right click and select 'Enable Indexing'.
Message Edited by Dennis Knutson on 07-03-2007 10:25 PM
Message Edited by Dennis Knutson on 07-03-2007 10:26 PM
Attachments:
Crude Build Array.PNG ‏4 KB
Better Build Array.PNG ‏6 KB

How to build a array with high sampling rates 1K

Hi All:
Now I am trying to develop a project with CRio.
But I am not sure how to build a array with high sampling rates signal, like >1K. (Sigle-point data)
Before, I would like to use "Build Arrary" and "Shift Register" to build a arrary, but I found it is not working for high sampling rates.
Is there anyother good way to build a data arrary for high sampling rates??
Thanks
Attachments:
Building_Array_high_rates.JPG ‏120 KB

Can't give a sample of the FPGA right now but here is a sample bit of RT code I recently used. I am acquiring data at 51,200 samples every second. I put the data in a FIFO on the FPGA side, then I read from that FIFO on the RT side and insert the data into a pre-initialized array using "Replace Array subset" NOT "Insert into array". I keep a count of the data I have read/inserted, and once I am at 51,200 samples, I know I have 1 full second of data. At this point, I add it to a queue which sends it to another loop to be processed. Also, I don't use the new index terminal in my subVI because I know I am always adding 6400 elements so I can just multiply my counter by 6400, but if you use the method described further down below , you will want to use the "new index" to return a value because you may not always read the same number of elements using that method.
The reason I use a timeout of 0 and a wait until next ms multiple is because if you use a timeout wired to the FIFO read node, it spins a loop in the background that polls for data, which rails your processor. Depending on what type of acquisition you are doing, you can also use the method of reading 0 elements, then using the "elements remaining" variable, to wire up another node as is shown below. This was not an option for me because of my programs architecture and needing chunks of 1 second data. Had I used this method it would have overcomplicated things if I read more elements then I had available in my 51,200 buffer.
Let me knwo if you have more qeustions
CLA, LabVIEW Versions 2010-2013
Attachments:
RT.PNG ‏36 KB
FIFO read.PNG ‏4 KB

Concatenate clusters to array with enums

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