Knowledge Base

11 Data Visualization

11 Data Visualization

Visualize The 3d Track

We assume at this point that you have completed the 3D analysis procedure (page 60). A 3D track chart opens on the screen.

Default views

By default, the track is viewed from above (X-Y view). To revert to this

view, right-click anywhere in the middle of the chart and select Reset to

Original View. Additional default views are: X-Z view and Y-Z view. To activate a view, right-click within the chart and select the option you require. Figure 20 Default view of the 3D track. 11 Data Visualization

Data points

Each point of the track is a sample originated by a pair of valid 2D EthoVision samples. The first point is marked by a green triangle, the last by a magenta circle. The color and style of the samples varies according to their position: Green star - For samples within the cone (1 in Figure 21) Magenta triangle - For samples in the buffer zone (2) Red dot - For samples outside the cone and buffer zone (3) Different blocks of valid samples are separated by a number of missing samples depending on what you have specified under interpolation (see page 71). Thus the time between the end of a red track and the start of the next is not fixed.

Odour plume cone

The cone represents the diffusion pattern of the odour plume throughout the test chamber. It is indicated by blue circles. The cone's top position is indicated by a blue cross. To change the shape and size of the cone, enter the appropriate values in Track3D (page 65), select Old calibration and click Start calculations. Figure 21 The sample points differ in style and color depending on their position. See the text for an explanation. 11 Data Visualization

Panning options

1. To move the chart, click the Pan button on the tool bar.
2. Click anywhere within the chart and drag to the position you require. If you have selected one of the default 2D views (X-Y, X-Z, Y-Z; see above), you can also pan the chart in fixed directions: right-click the chart and select Pan Options, then Horizontal Pan or Vertical Pan. Next, drag the chart as usual. To revert to normal pan mode, right-click, select Pan Options then Unconstrained Pan.

Rotating the 3D chart

1. Click the Rotate 3D button on the tool bar of the chart window.
2. To rotate the chart, drag the mouse over the chart.
3. To rotate the chart around the z axis, drag the mouse horizontally. To rotate the chart around the x axis, drag the mouse vertically.
4. To rotate the chart while viewing the previous orientation, right-

click within the chart, select Rotate Options and then Plot Box

Rotate. To rotate the chart continuously, right-click within the chart, select Rotate Options and then Continuous Rotate.

Zooming in and out

1. To zoom in and out the chart, click the corresponding magnifying glass button on the tool bar. 11 Data Visualization
2. Click within the chart one or more times, or move the mouse wheel to get the zoom level you require.

Visualizing specific data points

1. Click the Data Cursor button on the tool bar. The mouse pointer changes to a cross symbol.
2. Point to a specific sample, then click. A datatip opens showing the 3D coordinates of the sample and the time stamp. If you click the line connecting two samples, the coordinates of the nearest sample point are displayed. To display the coordinates of two or more data points, right-click the

chart, select Create New Datatip, then click the sample you want to

visualize, or press Alt and click the sample you want to visualize. To

remove datatips, press Delete.

Visualizing the track in multiple colors

You can visualize the 3D chart with points in different colors, based for example on speed. We advise you to open the raw data file (page 85) in

RapidMiner. You can download RapidMiner for free from the web site

https://rapidminer.com.

Editing the 3D chart

There are a few options to edit your chart before exporting it. 11 Data Visualization

From the File menu of the 3D chart window, select Export Setup. Make

the necessary changes, then click OK. To test a change, click Apply to

Figure. To return to the default chart, click Restore Figure.

Size (for printing) - Select the units you require, and enter the

Width and Height of the chart. This includes the title text and the

axis labels). To return to the original size, select Auto for both

options.

Rendering - Select the Colorspace you require. To change the

background color, select Custom color and there type in a letter for

the color you require (w= white, y= yellow, m= magenta, r= red, c= cyan, g= green, b= blue, or k= black). Choose the resolution of the

picture. De-select the Keep axis limits option if you want to stretch

the chart depending on the window size.

Fonts - To change font size, select Use fixed font size and enter the

size in points. Select Custom name and select the font you want to

use.

Lines - To change the width of the lines (including the track),

select Use fixed line width and enter the width you require. For more information, see the MATLAB documentation.

Export And Print The 3d Track Chart

Saving and exporting the 3D chart

You can export the chart as a picture file. To save the chart, from the File menu select Save, or click the Save Figure button on the tool bar.

In the File name field enter the name you require for the file, then from

the Save as type list choose the format, and click Save.

tip You can save the 3D chart as MatLab figure (*.fig), which you

can re-open, rotate and play back using Track3D. From the File

menu select Save As, keep the option MATLAB Figure (*.fig)

11 Data Visualization

selected, type in a name for this file and click Save. To re-open the

figure, make sure that a Figure window is open, and from the File

menu select Open.

Printing the 3D chart

To print the chart, from the File menu select Print, or click the Print

Figure button on the tool bar.

You can also add titles and change the text style by selecting Print

Preview from the File menu.

Play Back The 3d Track

You can play back the track in the Track3D chart. In this animation the subject is represented by a red circle which moves along the 3D trajectory at a user-defined speed. 1. Specify the playback speed: under Speed, click Normal for 1x, or select the second option and move the slider to the speed you require. 2. To play back the track, click the Start animate button. 11 Data Visualization 3. To pause playback, click Pause. To resume playback, click Resume. 4. To stop playback, click Stop animate. To replay the track, you must first click Stop animate.

Create A Video Of The 3d Track

With the Record function you can create a video of your 3D track that

you can play on a computer without Track3D. 1. Make sure that the 3D chart is open on your screen. Rotate and zoom in/out if necessary. 2. Under Record, click Preferences. The Preferences record box appears. 3. Under Resolution, choose the size of the video image in pixels. 4. Under Compression, choose one of the options: - None - Video is saved as a RGB raw bitmap AVI file. It gives the best image quality but also larger file size. Choose this option especially with high density of points in your 3D track.

In the field below, enter the Maximum file size (in MB) you want

to accept. 11 Data Visualization - Cinepak - Video is encoded using a Cinepak codec. In the field below, enter the Quality (1-100). The higher the value, the better the picture quality and larger the size of the resulting video file. 5. Click Start record. The chart window comes on top at the bottom-left corner of your screen, and track animation starts. The screen is captured according to the options selected. 6. When the screen recording ends, the Start record button becomes available again, and a text appears at the bottom of the Track3D window: 11 Data Visualization 7. The file is saved in the MCR folder. The file name is "AVI"+ date + time_n. The value n increases 1, 2,... if multiple videos are saved in the same minute.

Notes

The animation shows the odour plume cone, not the other user- defined zones. In most cases the screen capture only includes the chart (white area), not the title text.

If you choose None and the video file size exceeds the Maximum

file size entered in step 4, video capture will stop at that size. Therefore, the track will not be played back for its entire length. You cannot make a video from a 3D chart that was saved previously and opened via File, Open. You must repeat the analysis procedure in order to visualize the track in a new 3D chart. Next, make a video from that track chart.

After starting recording, check that the Start record button is

greyed out. If not, click it once more. In the table below you can see how much disk space a video requires. Frame rates: For Cinepak 8-12 frames/s, depending on quality; For Uncompressed 10 frames/s.

Resolution

Compression

Quality

Space

402 x 378 Cinepak 100* 6 MB/min None 320 MB/min 838 x 790 Cinepak 100* 17 MB/min None 1300 MB/min

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Source: Track3D 2 - Reference Manual (March 2025)