DPlot

villela · Joined: 27 Feb 2010 Posts: 12

I am a Labview programmer and I do not like very much the appearance of its polar plots. I would like to know how I can run a Labview application and the graphs get the appearance of Dplot graphs. I own a license of Dplot version 2.3.0.1.
Thanks.

DPlotAdmin · Posted: Thu Nov 11, 2010 9:45 am Post subject:

Sorry, but I don't know a thing about Labview. If it gives you the ability to call functions in external DLLs then you might be able to use the functions in DPLOTLIB.DLL with a minimum of fuss (after the initial setup). Otherwise you may be stuck with copy/paste.

I'm hopeful another Labview user will chime in here...
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AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

labview has a tool to make this easier. Tools->ImportShared Libaray. This tool requires a c or c++ header (thing.h) to be specified in order to produce the goods.

Otherwise, one can apparently use a "call libarary function node" to do it. The thing.h route would appear to be nicer.

Any chance of the required dplotlib.h?
ref: http://digital.ni.com/public.nsf/allkb/DCB90714981A1F148625731E00797C33

AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

I normally spell library like this, and not as in the previous post. Sorry.

DPlotAdmin · Posted: Thu Jan 13, 2011 9:57 am Post subject:

The dplot.h header file used in the C examples is probably the best starting point. If you haven't installed DPlot Jr, get it from http://www.dplot.com/dplotjr_setup.exe . After installing, the C header file will be in [dplot jr destination folder]\DPlotLib\C.
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AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

Looks good David. It sees the stuff in the header and appears to be digesting it. Ahh - seems to have got stuck in the middle. Looks like I'll have to mess with it a bit. Anyway, I think it is the right approach. Thanks

AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

In fact, if one has a little patience (I went to lunch), labview does its work and produces an lvlib with the required functions in it as VIs, except a few of the bitmap ones (further work). Dragging D plot Plot.vi onto a diagram and doing a "create constant" on the terminal for the Dplot structure produces a cluster constant with 914 elements in it- 99 slots for NP values, 99 slots for linetype values... etc.

So, a bit funny looking but I think it will work

jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

this is cool.

I am using the "Import Shared Library" function in LabVIEW right now to create a vi. It's taking a while (it shows it to be about half-way complete, and the CPU is cranking...)

So, it eventually finishes what it is doing?

Basically, I want my LabVIEW data acquisition program to automatically create DPLOT files instead of me opening up the data file by hand in DPLOT every time.

I think this will help me do it..... DPlot and LabVIEW seem like they would be two peas in a pod....

jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

It worked for almost all the functions except the bitmap functions mentioned above, and 3 functions I think I need. I got the following error report:

jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

okay, I changed the clusters in those 3 functions to "custom controls" in the "Configure VIs and Controls" dialog.... but I don't know what I'm doing.

help Smile

DPlotAdmin · Posted: Fri Mar 11, 2011 2:59 pm Post subject:

You're doing great. Keep it up! Smile

Sorry, I have no idea - I've never had LabView. If the tsunami didn't wash away our Aussie friend maybe he'll chime in here.
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jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

I think that by "custom control" LabVIEW wants me to create a little box that takes inputs for each of the variables in those functions.

So, for example, in the Plot() function, there's a cluster called "DPlot" and it looks like it has the following variables:

Version
hwnd
DataFormat
MaxCurves

and so on, and so on....

Those variables are "unsigned long" types, etc.

But then, further down, when you get to variables in that function like "NP" and "LineType," they say they are the data type of "unsigned long[100]"

What's the [100] for? Does it think it is an array or something? I think that's what is making LabVIEW choke when it tries to convert the "struct" datatype containing all these things to a "cluster," because it sees "unsigned long[100]" and says "what the hell is [100]?"

DPlotAdmin · Posted: Fri Mar 11, 2011 3:16 pm Post subject:

Those are arrays, and 100 is the correct size. (You can have up to 100 curves; NP[0] is the number of points in the first curve, NP[1] is the number of points in the second curve, etc.)

But what that means to getting this working in LabView I have no clue about.
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jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

yeah, that makes sense. LabVIEW apparently is not able to convert a datatype directly if it's something like a structure with nested arrays.

So, those 3 functions that need arrays within the structures have undefined structures.

Here is the Plot() function:

"DPlot" and DPlot out" are now custom controls, but I need to make them have all their data. (they need Version, hwnd, DataFormat, but they also need the NP array, etc).

Once I figure out how to do that, it should be okay. maybe.....

DPlotAdmin · Posted: Fri Mar 11, 2011 6:19 pm Post subject:

This is way outside anything I can even comment on, sorry. I'm hopeful AWaterman will shed some light on this.
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jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

yeah, see, I'm trying to create a custom control for the Dplot structure....

do I need to create 100 NP unsigned longs?

like,

NP[0]
NP[1]
.
.
.
NP[99]?

Because that's what LabVIEW does when it wants to put an array that was in a structure in C into a cluster. it puts each element into the structure individually.

Still playing with it....

AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

In spite of the best effortd of mother nature, we are still high and dry in Canberra (1800 feet elevation). I do feel for those poor folk in Japan at the moment.

How do you get a diagram into these posts? I wanted to do that and couldn't see how you do it. A picture is worth a 1000 words

I'll review what I did and try and respond to Idriss's stuff. I suspect that using the "create constant" option when mousing over a terminal may be the trick

DPlotAdmin · Posted: Mon Mar 14, 2011 6:12 pm Post subject:

Les,
You can only post links to images, not the images themselves. If you don't have an FTP/http site where you can post, send the image(s) to me and I'll make them available.
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jidriss · Joined: 11 Mar 2011 Posts: 8 Location: San Antonio, Texas

DPlotAdmin · Posted: Mon Mar 14, 2011 7:23 pm Post subject:

DPlotAdmin · Posted: Mon Mar 14, 2011 7:43 pm Post subject:

Images from AWaterman:

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AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

My labview (8.5) DID succeed in making Dplotlib labview library, and it issued the report at the end as follows
"Your generated files are installed in the following folder:
C:\Program Files\National Instruments\LabVIEW 8.5\user.lib\dplotlibx

Parsing header file warnings:
No errors/warnings occurred when parsing the header file.

No errors/warnings occurred when generating the wrapper VIs for this shared library."

The lib contains VIs as shown in the graphic list (David to display). I placed Dplot plot .vi and Dplot command.vi on the diagram and was then able to create the constant as a previoulsy described.

My library is called dplotlibx because it was my second attempt. I assumed it was not working when it took ages to create, and so I aborted the first. The secret was to go and have lunch while labview made the library.

Note that I have not gone the whole way and actually plottoed anything. I had (and have) other priorities so stopped once I had the vis appearing OK

DPlotAdmin · Posted: Mon Mar 14, 2011 8:45 pm Post subject:

Two more images from AWaterman (unfortunately it is still Greek to me):

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AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

If JIdriss wants my lvlib, I'm happy to zip it up and send it - just give me the mechanism.

DPlotAdmin · Posted: Tue Mar 15, 2011 7:05 pm Post subject:

Your e-mail address stored in the forums appears to be legit, so he already has that. In any case thanks very much for your input, and I'm glad you weren't washed away.

If I start making a lot more with DPlot then I'll be able to justify paying for LabView... so talk it up among your associates Very Happy

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AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

I am talking it up. I have a proposal to buy a couple of lcienses here in the pipeline right now. But as you know, government doesn't move quickly, even down here on the world's bottom.

AWaterman · Joined: 08 Jan 2006 Posts: 52 Location: Canberra, Australia

I'll wait to hear from jidriss. Incidentally, I used the ability to interface dplot and labview as an argument for buying dplot

Tebbe · Joined: 17 Oct 2012 Posts: 2

I realize this is a fairly old thread now, but did anyone get this to work to the point where you could pass data from LabVIEW?

I've created a D Plot Plot.vi and I am able to get DPlot Jr to open. If I run my vi a second time, axes and gridlines show up, but no data. I can provoke it to return a value of -3 or -4 by changing the Version and DataFormat, otherwise it always returns 0.

I noticed that AWaterman's DPlot cluster is brown, indicating that it is numerics only. Shouldn't this cluster also include the Legend, Label, Title, XAxis, and YAxis strings?

Tebbe · Joined: 17 Oct 2012 Posts: 2

I figured it out. For future reference, to convert a LabVIEW DPlot cluster into the DPlot struct you need to:
1) Unbundle the cluster
2) Convert the NP, LineType, and SymbolType arrays to clusters using "Array To Cluster". HINT: Right Click "Array To Cluster" to change the cluster size to the size DPlot is expecting (whatever MAXC is for your version).
3a) Convert each string in the Legend, Label, and Title arrays to a byte array with "String to Byte Array".
3b) Convert each byte array to a cluster, making sure to set the correct size.
3c) Create an array of these clusters, then convert those arrays to clusters. Legend, Label, and Title end up as clusters of clusters of bytes.
4) Convert the XAxis and YAxis strings to byte arrays and convert the byte arrays to clusters.
5) Bundle everything in the correct order and pass it to the Call Library Function for DPlot_Plot. The input parameter should be set to "Adapt to Type" with a data format of "Pointers to Handles".

You probably don't want to look at the final cluster. It's huge and caused LabVIEW to lock up for a few minutes while it figured out how to draw it.