Build array 250 values

hello all of you..
i have a little problem and i confuse
i want to fill an array with 250 values 1-D.
when it takes and the last value,then it will enable to do some calculations
and give me result.
is it some easy way to plot these values as a waveform on XY GRAPH?
and LABVIEW understand these values as a waveform?
thanks a lot ..

well, i made A/D to a signal and send values to PC via rs232 (25 samples /20ms or 250 samples/0,2sec)
i want to plot ,store, and do some calculations on that signal
to do calculate ,first, i must store 250 values
when i get and the last one,then get result.
that will happen all time.
i have some problems about plot on XY graph
(on chart works great)
i think labview don't understand it as a waveform.
also i want to pass through low pass filter,at this time i can't.
what can i do 1)when i take 250 samples then get result
and 2) how i make labview to undesrtand these samples as waveform
after all i will do some analisis on that signal.
thanks a lot

Similar Messages

Build Array keeps name of the last element but not the others. Workaround?

Hi there,
Sorry if this has been posted before, I did the search first but did not find anything.
Problem is that I have two setups that are identical and need to be controlled from a single vi. Since they are the same they are configured with the same sets of parameters so I decided to create a cluster of these and then build an array of the clusters. This way I need to only use one wire and if I need a given parameter I can easily get it from there (or so I thought) and also since I need to see if anything changes I can compare one wire instead of each one of the parameters.
The gui has the list of parameters then in the block diagram I bundle them appropiately, using "Bundle by Name" and then each bundle into an array using "Build Array". Problem arises when I index the array for the first setup and the use that to unbundle the parameters I need, using "Unbundle by Name" (though if I use "Unbundle" the same happens)and lo and behol, the ouput names are from the second setup, not the first.
Here is the curious thing though, even though the names are all wrong the values are correct. I could live with this but it is annoying plus it will make another user very hard to understand the diagram plus this is just a proof of principle to test with two, eventually there will be eight or even more and that is going to get really confusing.
Is there a way around this? Even if it is to change the names after unbundled.
Check the attached vi to see what I mean.
Solved!
Go to Solution.
Attachments:
Test Build Array Names.vi ‏11 KB

I think you are forgetting an important point about arrays. The only thing that can be different between each element of an array is its value. The array elements must all share the same properties. So that would include the names of the individual elements that make up the cluster that is an array element.
It appears that the last cluster that gets built into the array is the one that defines the names of the elements that are within the cluster element. You either need to give all elements of the array the same names within the cluster. Or use a cluster of clusters instead of an array of cluster to build your data structure.

Cascade two Build Array functions - what happens?

I found the the code shown in the attachment in a very complex VI that I am overhauling. Would someone explain to me what is happening with the "cascaded" Build Array functions.
I can see that the first Build Array function builds a 1D array of integers which passes to the second Build Array function which outputs a 2D array of integers but, since there is no Element or second Array input, I don't see how this works.
This is part of a subVI that is not embedded in a loop.
All the examples have at least two inputs. With one input there is no Concatenate Inputs option. There is some implicit operation here that I do not understand.
Would someone explain how this works?
Solved!
Go to Solution.
Attachments:
Cascade two build array functions.PNG ‏7 KB

You are taking a scalar value and creating a 1-D array with exactly 1 element.
Then you are taking the 1-D array and building it into a 2-D array, with exactly 1 element.
Since you can't concatenate something with nothing, the only logical mode for the Build Array would be to build it into an array of the next larger dimension.
You could add a third one, then you'd have a 3-D array with exactly 1 element. And so on.

Build array combinations

Hi
i have a 2 d array set of values with n columns and rows .
I need to build array with all the cell combinations .
Can u pls guide me with an example vi ?
Thanks

hi nithyamv
I need to build array with all the cell combinations Can u brief your query little bit more ,
by giving screen shot. or .vi you developed.
Indrajit
| [email protected] | [email protected] .

Build Array Question

Hi,
I am wondering how to build a selective array from a continually changing stream of data. For example in the attached picture, I wish to append to the array only even numbers. So the resulting array should be [2 4 6...]. However, I am aware that for a case structure, an output terminal is required, so instead my output reads [0 2 0 4 0 6...], since the default value in the false case is zero. Is there a way to build an array that will only append new elements when certain conditions are met? (in this case, the condition being if the number is even).
I am aware that you can use a sort array function block, then remove the zeros. Is there a better way to perform this task that I need? In my actual program, I need to record the value of the time at a couple values at the turn of the hour when certain conditions are met, then feed the new array to a graph. Thanks,
Adam
Attachments:
Build an Array.JPG ‏31 KB

You can just put the build array part into the case statement.
You can also switch the build array to concatenate inputs mode (right
click on it), and use arrays to output from your case statement (using empty
arrays when you don't want to add anything)
Ideally you avoid puting build array into a loop, since reallocating large arrays can really slow down a program (shouldn't be a problem for small arrays).
Message Edited by Matt W on 11-21-2006 08:27 PM
Message Edited by Matt W on 11-21-2006 08:28 PM
Attachments:
build array 1.PNG ‏15 KB
build array 2.PNG ‏15 KB

Build array element labeling

Hello,
I am using the build array function to make a large boolean array. How can I have the element positions labeled so that I can easily determine what bit in the array I am connecting to?
Regards,
Kaspar
Regards,
Kaspar

You didn't mention that in your problem statement. Also, you mentioned you're using Build Array. Are you interested in knowing the terminal position on the Build Array that you're wiring to? There is currently no way to do that, as they all have a name of "element" when you hover over the Build Array with a tip strip. How many values are you wiring to your Build Array, anyway? If there are so many that you can't keep them straight without labels, perhaps there's a more elegant way to deal with the code?
If not, though, perhaps you could include a decoration on the diagram separating every 5th element that could help you more easily determine what position you're at with the build array:
-D
Message Edited by Darren on 05-23-2007 03:09 PM
Darren Nattinger, CLA
LabVIEW Artisan and Nugget Penman
Attachments:
build_array_dec.png ‏9 KB

Error in file export when order of elements in build array changes

Hi everyone,
A while ago I wrote a vi file which does the following:
At first it initializes a camera and chooses a region of interest (ROI). Data out of the ROI will be discarded.
Then it raster scans a motor stage in x and y direction, in bidirectional mode (meaning that x alternates between scanning from left to right and right to left as y is inreased).
For each point of the scan, the spectrum is collected, which is then integrated in lambda to give an idea of the total intensity.
Then the intensity is plotted, along with the spectrum at each point.
The final results are exported in a text file.
The problem:
If I flip the order of the wires in the "build array" before the file export, placing the Total Count (intensity) wire in place of the Spectrum wire, the file export fails. What I mean by "fails" is that the .txt file contains characters that look like chinese!
Why is that?
I attach my .vi as well as two screenshots which demostrate the problem.
Solved!
Go to Solution.
Attachments:
correct.png ‏182 KB
Wrong.png ‏180 KB
1.7z ‏119 KB

mikeporter wrote:
Hey Jeff... The changes you recommend are all good (and necessary) but the thing I'm stuck on is that regardless of what happens to the floating point data, there's that built-in VI that changes it to string representations of the numbers. And as I understand it, that is where the problem is.
Mike...
PS: Coming to NI Week?
Not this year
What scared me was the sgls on a SLs with no wire branch to force a data copy which, would force LabVIEW to preserve the sgls since the SL might need to be used again then, they get all mixed up building arrary out of mixed coerced sgls and dbls. With the potential of a miss-reussed buffer (not uncommon in 2011) confusing the string operations in the write to spreadsheet. The problem of course, must exist outside of write to spreadsheet file since it only exhibits with a build array element order change. Or, we all are halucinating (Possible alternate theory)
Jeff

Rookie Question: Swap values? Declare an array and values of its indices?

Hello,
I hope this is the right forum: I have a simple Java Problem but i do not get it.
Is like that: I have to swap values within an array e.g i have one array with 3 indices. Indice 0 (the first indice) has value 12. The middle indice has no value, and the second indice has value 9. How to swap 9 to 12 and 12 to 9 without direct swap, in other words, by using the middle indice that has no value or is zero? And how do i write it in an array?
My other questions: How do i Declare an array and values of its indices?
I hope this is the right forum or site at all, in cas enot, i hope you still can help or give me links that could help. I really need this.

Hi Rookie,
     http://forum.sun.com is the best place to get answers for your queries.
     Answer to you first question:
     array[0]=array[0]+array[2]; // array[0] will have 21, because 9+12.
     array[2]=array[0]-array[2]; // array[2] will have 9, because 21-12.
     array[0]=array0]-array[2]; // array[0] will have 12, because 21-9.
     Hope your first query is resolved.
     I will answer your next query in my next reply.
Thanks & Regards,
Charan.

How to avoid Build Array function inside a For (while) Loop?

Hi there,
I have a simple question about how to avoid using Build Array function inside the loop. Now I want to remove the Build Array funtion inside the loop to improve the performance (To get better memory management). Any idea how to do that?
Thanks a lot!
Warmest regards,
Chong

It's been my experience that using the auto-indexing to build an array
on a For loop is just as good as initializing and replacing elements.
The For loop knows before it runs how many iterations it has to run and
can allocate the array ahead of time.
You're better off initializing and replacing when using a While loop
because it does not know how many iterations it will run and can't
pre-allocate the array ahead of time.
Ed
Ed Dickens - Certified LabVIEW Architect - DISTek Integration, Inc. - NI Certified Alliance Partner
Using the Abort button to stop your VI is like using a tree to stop your car. It works, but there may be consequences.

Passing array of values from front panel to menu

I am working with a group programming a multichannel current stimulation device and we are currently having trouble setting up the run time menu. The burning question that we have is trying to figure out how to pass an array of values from the front panel to the menu that we are setting up in the block diagram, any advice?
Thank you

Take a look at this. Its just a simple menu update using a for loop. Uses whatever your values are as the item tag and item names. Remember, item tags need to be unique. This specifically goes under the sub menu of channel, which has to be created before.
Attachments:
menu.vi ‏12 KB

Populating array of values in GlobalContainer.

Dear Friends,
I have a doubt in excecuting the GlobalContainer in UDF. It will be great if you guys help me out in solving it.
I'm passing some array of values into UDF.After doing some validations I need to set these values in array of Global Container.Later in other UDF I've to retrieve the array of values from the Global Container.
Can you guys shed some light on what logic needs to be done ?
Best regards,
raj.

Use Java Sections instead of GlobalContainer.
Check this link: http://help.sap.com/saphelp_nw2004s/helpdata/en/49/1ebc6111ea2f45a9946c702b685299/frameset.htm
on the java sections part.
Basically you define the global variable in the Global Variables section. For example:
List list = null;
Then in initalization section, you initialize the global variable:
list = new Vector();
Then you could have your UDFs filling and later reading the variable (just read/write the <i>list</i> variable).
In the Cleanup section, you can do for example:
list.clear();
Regards,
Henrique.

Best Way to Create Array of Values From ArrayCollection

I often use Arrays of values from ArrayCollections in my
application in order to facilitate faster performance when
filtering other Collections.
For instance, let's say I have an ArrayCollection of Objects
with the properties "id", "name", "label", and "isActive". What
would be the best way to get an Array of all the "id" values?
Right now, I am looping over the ArrayCollection, and adding
the value of the property I need to an Array using Array.push().
For larger Collections, this seems like overkill. I was wondering
if anyone knew of some quicker way to get an Array of values of one
property from an Array Collection.
My current method for doing this is attached below...
Thanks.

No, that won't work - toArray() simply returns the entire
Collection as an Array.

Updating a JTable with an array of values

Ther is a constructor that allows for the cretion of the table with an iniital array of values. However subsequent updates of blocks of data- say you received an array of updated data form a database- reuiqre you to update ince cell at a time. Is ther any way fo updating a whole block at once. I should point out that I am asking this because I am using JTables in the Matlab programming environment where arrays are the basic unit and looping through is a comparatively slow process

Yes, you can extend the AbstractTableModel and write a method for updating a whole block.
lets say you've got a Vector with Float[] arrays as elements to hold a 2D array of Float. The you could write:
      TableModel dataModel = new AbstractTableModel() {
            public int getColumnCount() { return col_names.size(); }
            public int getRowCount() { return data.size();}
            public Object getValueAt(int row, int col) {
               return ((Float)((Float[])data.elementAt(row))[col]).toString();
            public String getColumnName(int col) {
             return ((String)col_names.elementAt(col));
            public Class getColumnClass(int col) {
             return String.class;
            public boolean isCellEditable(int row, int col) {
              return true;
            public void setValueAt(Object aValue, int row, int col) {
               try {
                 Float fv = Float.valueOf((String)aValue);
                ((Float[])data.elementAt(row))[col] = fv;
               } catch (Exception ex) {
            public void setBlock(Float block[][], int row, int col) {
               // copy the Arrays with System.arrayCopy into data
      };PS: I don't know, if the above is correct written, havn't test this. But I hope you can recognize the idea behind it.
wami

Is it possible to create a 1 D array with the "build array VI"? when receiving random number

Hello all,
Is it possible to create a 1 D array with the "build array VI" when receiving random number?
I am receiving random data and the build array VI always create a 2D array which might cause some problem if you want to compute certain type of operation after.
Any example will be welcomed.
Thank you,
Israel

Hello Lynn and Yamaeda
First I want to Thank you Lynn for your linguistic contribution indeed "Build Array" is a primitive and not VI, thank you for the education. In reality what I am doing is simple.
I have two arrays of complex elements Array1 and Array2.
Array1 conains the complex elements ""(a0+ib0) ; (a1+ib1) ;...(an+ibn) ;
Array2 conains the complex elements ""(c0+id0) ; (c1+id1) ;...(cn+idn)
What I want to do is the multiplication of the first array by the conjugate of the second array element.
Array1*(Conjugate Array 2)" for the first element the results is "(a0.C0-b0.d0) + i(b0c0-a0d0)" and the etc...
and then taking the square root ([(a0.C0-b0.d0) power of 2]) + [(b0c0-a0d0) power of 2])
I was wondering if there were some dedicate primitive that could solve the computation above which is the cross correlation in Frequency domain.
Thank you very much.
Israel

How to use 'build array' (concatenate) to create a array horizontally?????HELP

I want to link nine arrays whose dimension is 2*2 horizontally，but the function 'build array' (concatenated way) made them vertically.........help me please..........maybe this is too simple.........since I am only a students who learnd labview only few months..
Solved!
Go to Solution.

A transpose operation only solves certain scenarios, but you don't give enough information on what you actually want.
For example, of you have 3 2x2 arrays:
a1 a2 b1 b2 c1 c2
a3 a4 b3 b4 c3 c4
What should the final vertical result be?
a1 a2
a3 a4
b1 b2
b3 b4
c1 c2
c3 c4
or
a1 a3
a2 a4
b1 b3
b2 b4
c1 c3
c2 c4
Or something else?
Please be much more specific. Maybe even attach a small VI containing typical default data.
LabVIEW Champion . Do more with less code and in less time .

Build array 250 values

Similar Messages

Maybe you are looking for