Polar plot help

I'm working a project where I need to plot X & Y data to a polar plot. Actually, what I really want is to plot X-Y data on a compass rose, and show 'clock" position instead of angle headings...but I can fake that well enough for now...
Attached is my test vi for plotting to the polar plot. I've repalced the standard LV polar plot with a version available in one of the support forums that plots points instead of lines. Looks right to me..but no data plotted Any hints or direction?
Also, I ideally want to keep continually plotting data points - one set of coordinates after another. Any thoughts on the best way to do that? While loop maybe? I used to use labview prtty regularly, but it's been a while, so forgive me if these are easy questions.
Thanks!
Attachments:
polar_test.vi ‏41 KB

Updated vi attached for my polar plot test.I've replaced the modified "polar plot" vi with the original labview one. I can see data passing through everywhere, right to the plot itself...just don't see anything showing up. Is there something I'm misunderstanding about how to use the polar plot?
Attachments:
polar_test.vi ‏63 KB

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Polar plot of a data matrix....help is needed

Hello,
I'm working on an Ultrasound project, the data coming from the device is transmitted through a USB driver to the PC. I made a VI, that open a connection with the USB device and recieve the data. The coming data are recognized by the LabVIEW as stream of strings, so, i converted the data into a bytes using "string to byte array" function, then I used the function "reshape array" to reshape the data bytes into a 512x64 matrix which represents the no. of samples per ultrasound line times the no. of ultrasound lines.
I plotted the data on an intensity graph function and it worked, but the problem is that the data or the matrix must be plotted as a polar plot, not as a cartesian plot.
The problem is that I want to convert each single pixel (byte) of the (512x64) matrix from having (x,y) coordinate into a pixel that has (r, angle) coordinate.
can you help me plot these data in a polar plot. If any body has any suggestions please help.
best regards,
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Attachments:
US_VI1.PNG ‏17 KB

Multiple posts: keep discussion to this thread: http://forums.ni.com/ni/board/message?board.id=170&thread.id=337220

How can I change the Y-axis (circular) grid spacing, in Polar Plot VI?

When using Polar Plot VI, I need more control over the plotting parameters. This means tweaking the sub-VIs in various ways. What I need to do most is make the polar magnitude axis less busy, i.e. only draw circles every 10 instead of every 5 divisions, when using a range of 0 (outermost) to -80 (innermost).
The magic 'magnitude axis subdivisions' variable seems to be generated in Calc Scale Specs sub-VI, and output as an array of clusters, but I can't quite see how it's created and from what.
Please can anyone help me gain control over the number of magnitude division circles generated?
Many thanks!

I think if you go inside the Calc Increment.vi and modify the Increment output terminal it might change what you want to see. Try putting a multiply by 5 or ten into the case structure for when the log is false.
Attachments:
polar plot calc increment.jpg ‏90 KB
modify calc increment.jpg ‏104 KB

How can I increase line width on polar plot?

The lines plotted on a LabVIEW 6 polar plot (picture control) are very thin and do not show up well when printed. I would like to increase the line thickness (as can be done easily on the graph controls), but looking through the polar plot VIs, I cannot find any obvious way of doing this.

The polar plots basically use the picture control to draw the lines on a plot. To increase the thickness of the lines you would have to draw another line right next to the line. I'm sure this could be done, but would require alot of messing about with the drawing subVI's to draw all lines in duplicate.
Alternatively you could plot the graph twice, but the second plot has an origin 1 pixel out. This will double the thickness on the screen, but i dont know what it will print out like. See attached example in LV 6.0.
Another thing to try is change the plot colours. You can make the gridlines black (instead of grey), and paint the background white. This makes the lines show up much better. I will also include this in the same example.
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Attachments:
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Problem using read from spreadsheet file and polar plotting

Hi to all labview users,
i am a beginner in labview and i am trying to do a polar plot.
i read the polar plotting example in labview and it was straightforward.
I used "write to spreadsheet file" to gather data.
and they are in the following format
13 10
4 20
8 30
....etc
now. i tried using "read from spreadfile" to get the data into a array, then using "array to cluster" to convert the array into cluster, so i could connect it to the polar plot block
however, it kept saying i couldnt connect that way, because polar plot uses 1-d array with cluster of 2 element and my source is a cluster of 9 elements....
but doesnt the "read from spreadfile" block give me a 1-d array? and where does that 9 come from? i only have 3 rows and 2 columns in my data file....
any guidance would be greatly appreciated.
thx alot
Happy guy
~ currently final year undergraduate in Electrical Engr. Graduating soon! Yes!
~ currently looking for jobs : any position related to engineering, labview, programming, tech support would be great.
~ humber learner of LabVIEW lvl: beginner-intermediate

Helllo,
I've made an example to try to help you with that question.
Notes:
- the file must have values separeted by tab
- reading the values from file as you mentioned using "read from spreadfile" you'll get a 2D array and not 1D;
Software developer
www.mcm-electronics.com
PS: Don't forget to rate a good anwser ; )
Currently using Labview 2011
PORTUGAL
Attachments:
Read Table and plot polar graph.vi ‏26 KB
teste.txt ‏1 KB

I would like to use a polar plot in the application now I am developing.

Is there any kind of custom control or FP wich allows me to implement this kind of graph with CVI ?. (of course without doing Rec 2 Polar transformation and PlotXY).
Thanks in advance,
José M.

There currently is not a custom control for doing polar style plots in CVI. There is only one for smith charts. You can use the standard 2D-graph to create polar plots with the help our analysis libraries, or if you need a more custom display, you could draw your own plots in a canvas control.
Best Regards,
Chris Matthews

Multiple polar plots into a 3d plot

my test measures a light source, for each iteration (of the test) the detector moves up in elevation 5 deg (starts at 0 deg) and takes a data point every 2.5 degrees in azimuth (for a full 360 deg). My data array is a 3d array where on each page I have 3 columns azimuth, elevation (the elevation is constant for each iteration) and measured data. The question is: I cannot seem to plot it into a 3D graph...polar plot no problem...does any one have any insight?

“Create color map.JPG” illustrates one way to create the map for the forth dimension.
“Set Axis Range.JPG” how I manipulated the axis range and properties. Note: It appears all CW 3-d graph items start counting at “1” not “0”.
“Add Cursors.JPG” shows the cursor work.
I hope this helps,
Ben
Message Edited by Ben on 09-24-2005 03:48 PM
Message Edited by Ben on 09-24-2005 03:49 PM
Message Edited by Ben on 09-24-2005 03:49 PM
Ben Rayner
I am currently active on.. MainStream Preppers
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Attachments:
Create color map.JPG ‏37 KB
Set Axis Range.JPG ‏71 KB
Add Cursors.JPG ‏62 KB

Polar Plot Problem

Hello!!!!
I have created a Polar plot, but there is a line that shouldn't be there, what do I have to modify, so it shows exactly what I want??? I Have attached a picture of the graphs that I want, and my example VI, I hope someone can help me.
Sorry, The arrays have to be filled out whit the next info:
I: -1, 1,-1,1
Q:1,-1,-1,1 THIS WAY IT does what I need.
Saludos.!
Mensaje editado por Special K
Attachments:
img030.jpg ‏305 KB
graficar2.vi ‏43 KB

Special K wrote:
Im using LABVIEW 8.0 how can I create my own polar plot??
You would need to use the picture functions to draw your graph, in the same way that the Picture Plot VI does. If you open up that VI you will see how it's done.
Have you seen the images of what I want to obtain?? Is it possible to create those graphs??
Yes. And yes. The "how" is a different matter. It's quite trivial to create an XY graph to draw your points, so that's why I suggested to use that. If you do not know how to draw an XY graph, open the Example Finder (Help -> Find Examples) and search for "graph". You will see lots of examples on graphs, including one for XY graphs. All you need to do is provide 4 points to the graph, and change the plot type to "scatter" so you just get the points instead of lines. Pretty simple.

Colour in area underneath a curve on a polar plot

Hi i have made a VI that shows a curve on a line, i have also made a vi that outputs a mpeg video of the graph panning through all of its values, what i was wondering was if it was possible to fill in the area within a curve? I've managed to set the line colour, but i am unable to find anywhere that lets you set area colour.
Many thanks.
John P.
VI attatched, bits cluttered, but the polar plot is clearly visable at the center.
Attachments:
Cosine Lobe Model.vi ‏98 KB

Very nice unclebump,
You get 5 stars for that one To help people new with LabVIEW I decided to attach a picture showing you where to navigate to make the change. You need to change the logic constant from false to true in the Polar Plot Data.vi (Labeled Polar Data) under the Polar Plot.vi (No Label just a picture of a polar plot). The plot comes out filled because it is a multiple line graph drawn in a picture node with the line fill option on.
Regards,
-SS
Message Edited by ShotSimon on 08-27-2008 09:25 AM
Attachments:
Polar Filled.PNG ‏50 KB

How do you get the polar plot VI's to work correctly?

I have the data in a file and can see the correct data when placed on a smith chart, but not on the polar plot. It looks like it is mirrored on the Polar plot.

There are a couple of examples hat come with LabVIEW that might help you. They can be found under Help >> Examples >> Advanced >> Picture Control >> "Polar Plot" and "Simple Smith Plot". As a way of comparing the two different plots, I had them plot the same data points. It looks like if you have a lot of data points with a lot variability then you want to use the Polar Plot. The following webpage may provide some infor regarding smith plots:
http://zone.ni.com/devzone/nidzgloss.nsf/webmain/80EC3CE5F229DB818625686A0078B8D9?OpenDocument
Chris_Mitchell
Product Development Engineer
Certified LabVIEW Architect

Polar plot..gives a straight line

hello
i use labview 7.1
i have connected a polar plot vi....done all the connection as per the example vi
but i dont get the plot
i plotted from -180 to 180
i dont get the plot properly..
my magnitude values varies from -39 to -40
can any one help me..

Please attach your code so we can see where the problem is. Thanks!
LabVIEW Champion . Do more with less code and in less time .

Polar plot scale numbers "truncated"

I have a strange problem when using the polar plot VI.
Labview 2012 latest SP, running on a cRIO9074. I'm running a servo motor for one revolution while measuring the runout on an armature using a linear position sensor.
The data looks good, but for some reason, the scale labels truncate after two decimals, no matter what I set the precision to. I'm sending it a cluster of two double precision arrays.
When I run the Labview example, it works fine I can change the number of decimals viewed to 10 if I need to. I've tried keeping everything the same as the example.
Any ideas?
See picture.
The sample VI works fine, (I can set the precision to 6 and I will see 6 decimal positions. )

Thanks for the response, Kurt. With the help of a colleague, we were able to determine that this behavior is only when the VI is running on the cRIO.
(I think it was called "Polar Plot Demo.vi", but yes the VI is "Polar Plot with Points Option.vi"
We verified this by running the example vi first from windows (works fine), then ran it on the cRIO. On the cRIO it truncates decimals depending upon what font size you use. If you use a REAL TINY font, it will include more decimals. When running in Windows, the graph appears to move left to accomodate for more decimal place. When running on the cRIO, it appears to cut the picture off on the right side.
Following is our setup, but as stated above, we sent the demo program to the cRIO (didn't use any I/O) and the problem occured.
We're using Labview 2012, latest updates applied.
Modules are:
NI-9411 to read an Ono Sokki position sensor (quadature output from two channels, resolution is .0001 mm.
Ethercat set up using the "getting started" manual for the NI supplied AKD servo drive and motor.
All hardware works fine and data collected looks good. Test is to turn motor and collect servo position and linear encoder position.
Data has 4 decimal places coming in.

Polar plot with legend points

I can put one Polar Plot with legend in points?
Case:
I have magnitude and phase arrays for build polar plot and i want put rotation legend in each point of measurement. Then we have 3 arrays (magnitude, phase and rotation), but rotation need stay like legend for each point.
Somebody already do it?
thx for tip.
Leonardo de S. Cavadas
Maintenance Engineer and Inspection - Bureau Veritas do Brasil
Engineer Metallurgist with emphasis in Advanced Materials
Technologist in Computer Science

Unclebump,
i do one simple modification to be possible add rotation value to image, isn't better solution but i think that i'm near to solution way. Look these VIs, Re-link is necessary.
Leonardo de S. Cavadas
Maintenance Engineer and Inspection - Bureau Veritas do Brasil
Engineer Metallurgist with emphasis in Advanced Materials
Technologist in Computer Science
Attachments:
Plot Polar Data with Legend.vi ‏74 KB
OtherPolarPlot.vi ‏67 KB
Polar Plot with Legend.vi ‏75 KB

How to interpolate impedance measurements in a polar plot

Hello,
I do impedance measurements and plot them afterwards in a polar plot (see attached VI). Because of a sharp resonance it is hard to get a high resolution there.
- Is it possible to do an interpolation between the the measured points?
Thanks a lot.
Best regards,
Michael
Solved!
Go to Solution.
Attachments:
Interpolation.vi ‏47 KB

Take a look at the attached. I created an array to resample the data based on the data itself and then used the Resample (constant to variable) to generate interpolated data. This way the resonance is interpolated with more resolution than other locations. Does this do what you want?
There is a constant on the block diagram that controls how much more the resonance will be interpolated.
Message Edited by rpursley8 on 03-22-2010 12:02 PM
Randall Pursley
Attachments:
Interpolation-1.vi ‏76 KB

3D Polar Plot

I want to plot a 3D Polar Plot with Angle Axis as Angle, Radius Axis as Frequency and a third axis representing intensity at that point. For the snap shot of the image i have attached a .jpg file. Give me a perfect solution as soon as possible.
Thank You in advance
Attachments:
3D polar.JPG ‏22 KB

Hi 3D Polar,
well, you could use an intensity plot with embedded background graphics for the grid. Then you only have to plot the intensities after converting polar to rectangular coordinates.
Asking for a "perfect solution" is like wanting all for nothing...
Best regards,
GerdW
CLAD, using 2009SP1 + LV2011SP1 + LV2014SP1 on WinXP+Win7+cRIO
Kudos are welcome

Polar plot help

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