Labview array to graph

I am reading data from modbus and have an array of data that I need to graph, deepending on the iteration of a for loop I want to direct the data to the right struture and plot it.
What plot should I use, x-axis is time in all cases. Should the array be unbundled first or masked instead?
Solved!
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Attachments:
FPI_2.vi ‏27 KB

Well, some of your charts seems to have multiple traces, thus you need to rearrange the data a little bit. Here's one quick attempt, but please modify as needed.
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Attachments:
ArrayMOD.vi ‏16 KB

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How to convert from array to graph ?

how to convert from array to graph ?

A graph will accept an array of numbers. Do you have an example of what you are looking for?
And since somebody mentioned tutorials...
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How do I pass a 1D LabView array as a pointer to an array in a C DLL?

Hello,
I am trying to pass a 1D Labview array of DOUBLE to a C DLL which is expecting a pointer to an array of DOUBLE. I have read that LabView stores arrays as a pointer to a pointer and that the first element of a LabView array is actually the size of the array. So I think my question is then how do I dereference the first pointer and pass in a pointer which points to the second element in the array?
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Thanks!

Hi justyou,
There are many, many resources on this topic, so I will guide you to the two most useful ones:
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Pointer to LabVIEW Array

LabVIEW memory management question:
Question Part 1: When I write a C .dll that takes a LabVIEW array,
LabVIEW passes a pointer into LabVIEW's memory to the array to C.
Can C return the pointer to me (e.g., not the array I passed in, but
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http://www.averna.com

Part 1: I must confess that I don't understand your question. Pointers and arrays are very closely related in C so I'm not following the sequence. So I don't know if the following applies, but here is a possible answer...
The pointer to a LV array that is passed to a call library node is valid ONLY during that call. Once the call to the DLL completes, you should consider that pointer value invalid. You can, of course, make a copy of the array and return a pointer to your copy - but LV won't know what it is. It definately won't show up in LV as an array. However, you can pass that pointer to the copy around to other DLLs as much as you want.
* Don't forget to free the copy. If you make a copy of the array, you own it - therefore you must free the memory of the copy at some point *
Part 2: Easier to answer.
* If you want LV to convert your pointer to a LV data type (such as a LV array): Take a look at page 2-4 in the "Using External Code in LabVIEW". In almost all cases we do not support pointers. The only exceptions are the ones shown in the Call Library Node configuration. For arrays, notice that if you want to return an array to LV, we have our own defined data types for this - read up on the CIN section for more information.
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Did this help?
Message Edited by Lycangeek on 08-10-2005 02:12 PM
Brian Tyler
http://detritus.blogs.com/lycangeek

How to create and wire an array of graphs

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Hello,
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acquire_n_scans_block_diagram.bmp ‏628 KB

If i load 1GB file in labview array, it shows memory full. How tom handle it?

if i load 1GB file in labview array, it shows memory full. How tom handle it?

Don't read it all at once. Just read the parts you need when you need it.
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Row or columns of 2d array to graph

Hello
I tried to plot the values of a certain row of a 2d array in a xy graph. The x-axis should display the column-indexes and the y-axis the values of the elements of the row. The rowindex can be selectable by the user.
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Thx
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This should Do
Look at attached pic
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regards
Dev
Message Edited by devchander on 09-06-2006 04:31 AM
Attachments:
xy_2D.PNG ‏8 KB

Labview Intensity Charting/Graphing

How do you get an array with three columns of data to be 3 individual arrays and then graph them in an intensity graph/chart? I am pulling data from tcp and it is output as a comma separated string and a carraige return to denote an end of variables so the output in the data stream looks like:
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Attachments:
TCPGraphing.vi ‏40 KB
labview.png ‏108 KB

If I understand correctly, you will want to initialize a 2D array of the correct size for your data filled with zeros. As the data is read in, use the Replace Array Subset to replace a zero with the new data. The X and Y coordinates will determine which element of the 2D array to replace with the associated Z value. Something like the attached maybe?
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Attachments:
Replace.png ‏20 KB

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Generate digital pulse from your D I/O to control the relay. With Digital High State, the mechanical arrangement will connect the COMM to "NO" .... and you will get your programmable Ground. (in your case NC is not necessary I hope)
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Relay.PNG ‏8 KB

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Greetings.
I tried to plot DateTime string array VS Numbers array with no success in the XY Graph object.
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Solved!
Go to Solution.
Attachments:
Graph.JPG ‏93 KB

You could read the file line by line and use the scan from sting function to convert to a timestamp.
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How to optimize the memory for a large labview array?

I am running LabView on Windows XP with 4 Gb of RAM. The array is 51X256X256 complex numbers, but I want 300x256x256. The program runs out of memory when I use more than 51-53 arrays of 256X256. I do not know how to use the in place element structure to modify the vi below. The unbundled/ bundle structures do not present symmetry. Anyone can help me with this? Thanks!
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Attachments:
array3Dc.JPG ‏22 KB
array3Dc_front.JPG ‏58 KB

Norbert,
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Attachments:
data3Dc comp.vi ‏19 KB

Continous ramp generation in labview using XY graph

hi...i want to generate a continous ramp signal with XY graph but not by using charts.....because oscilloscope do not support a chart by using DAQ.....so please tell me a solution.

ankit26290 wrote:
because oscilloscope do not support a chart by using DAQ
Here are you referring to a 'software based oscilloscope'...??
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LabVIEW 8.0 Graph Scaling

Hi,
I generate an array of random numbers displayed on a Waveform graph. If I do the same thing during 100s, i have of course 0 to 100s on the Xscale.
I'd like to display the valve of the array by range of 10s. First, I display the first ten secs, then the ten next ones and so long.
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Test graph.vi ‏41 KB

Hi
Basically because you have "Autoscale X" activated. In addition, you do have not a defined order of execution. You do not know whether the graph is updated first or the scale is modified.
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Don't be afraid to rate a good answer...
Attachments:
Test graph.vi ‏42 KB

Labview.ini and graph rescaling

Hi everyone,
I'm using Labview 71. and 8.0 on Mac OSX.
It used to be (under Laview 6) that to disable graph rescaling a one line labview.ini file would do the job. The one line would be
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PGH wrote:
It used to be (under Laview 6) that to disable graph rescaling a one line labview.ini file would do the job. The one line would be
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Pointer Manipulation: Wrap Around/Rollover/Rotation of LabVIEW Arrays and Waveforms???

I know we can't use pointers in LabVIEW, but I was wondering if there's any way we can do wrap-around [or "rollover," or "rotation"] of Array [or Waveform] values without having to make copies of the Array [or Waveform]?
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2nd (1/5)th: 2nd second's worth of data
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Thanks!

> Ideally, such a VI would have two inputs: {old Array, new starting point}, and one output: {new Array}.
Have a look at "rotate 1D array" in the array palette (second row, fourth column).
(Sorry, I dont use waveform data).
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Labview array to graph

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