Balloon Plots

[LVCoder]

Hi,

I am trying to plot 3D balloon aka 3d directivity plot in LabVIEW but I am unable to.

The plot looks like this:

I tried plotting the data on the surface and the mesh 3d plots but both the plot take 2D array as its z-axis input. Thats the problem I am having. My z-axis is a 1D array of loudspeaker data at 50 Hz.

Attached is the loudspeaker data that I want to plot on a 3D plot. The 1st column is the points along the horizontal axis, 2nd column is the points along the vertical axis and the 3rd column is the loudspeaker data at 50 Hz.

Could someone help me in plotting the data on a 3d balloon plot?

Thanks,

Ritesh

[altenbach]

Use a "3D parametric surface graph".

[LVCoder]

I used 3D Paremetric graph and still it doesn't look like a balloon graph. Attached is the vi.

[fargoland]

Hi, 

Aren't you missing some data in the VI? 

Based on the data you shared with us. 

[LVCoder]

The data that I am trying to plot is stored in a 2-D array. The 1st column stores the degree of X-axis, the 2nd column stores the degree of Y-axis and the third column is the sound pressure level of the speaker at 400Hz.

[LVCoder]

I converted the cartesian coordinates to spherical coordinates and changed the coordinate system of the plot to Spherical.

It might be what I want but I cannot confirm it because I can't see the graph as a surface plot. 3D parametric graph just connects the consecutive points using a line but I want to view to on a surface. And I could not find any option under 3D Graph properties to view the graph on a surface instead of connecting points using lines.

Does anybody know how to view 3D parametric graph on a surface?

[alexderjuengere]

Oh, I just realized there is another 3d parametric surface plot, which is a bit hidden:

When I had to use it, I use the "3d graph.ctl" which is found in

"..National Instruments\LabVIEW 2015\vi.lib\Platform\3dgraph.lib"

to spawn the CW 3d graph indicator on the frontpanel.

The CW 3d graph has the following context menu:

But it looks like this graph needs more data to use the option "surface"

I guess you have to do something more sophisticated than passing your 1d array data into a 2d array

e.g. some kind of interpolation

[alexderjuengere]

this looks promising: http://www.ni.com/tutorial/4984/en/

Another way of thinking about the 3-D parametric surface graph is to think of the arrays as one 2-D array of 3-D vectors, (rather than three 2-D arrays of scalars). With this concept, we can easily see that the 3-D graph draws a rectangle for each set or four adjacent elements of the array. In the pictures below, we see a portion of this sphere's data array represented as a 2-D array of 3-D vectors. Notice that every adjacent cell generates a rectangle on the 3-D representation.

[Ben]

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@alexderjuengere wrote:

this looks promising: http://www.ni.com/tutorial/4984/en/

Another way of thinking about the 3-D parametric surface graph is to think of the arrays as one 2-D array of 3-D vectors, (rather than three 2-D arrays of scalars). With this concept, we can easily see that the 3-D graph draws a rectangle for each set or four adjacent elements of the array. In the pictures below, we see a portion of this sphere's data array represented as a 2-D array of 3-D vectors. Notice that every adjacent cell generates a rectangle on the 3-D representation.

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Yes, the secret is how you organize the data you present to the graph.

I have not worked much with the new versions of the 3D plotting

Spoiler

early versions sucked, bad performance little documentation and few features

but the basic ideas should be close to the old CW3D graphs. I put together a collection of the threads related to 3D graphs that can be found here.

Not sure if that helps,

Ben

[alexderjuengere]

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@LVCoder wrote:

The data that I am trying to plot is stored in a 2-D array. The 1st column stores the degree of X-axis, the 2nd column stores the degree of Y-axis and the third column is the sound pressure level of the speaker at 400Hz.

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Do I get this right, a Ballon Plot is a series of individually deformed circles ("polar plots") aligned on an axis?