CUSTOMIZING 3D GRAPHS AND CHARTS IN LABVIEW
CUSTOMIZING 3D GRAPHS
The 3D graphs have many options that you can use to customize them, including 3D plot styles, scale formatting, grids and plot projection. Because the 3D graphs use ActiveX technology and VIs that handle 3D representation, you set options for the 3D graphs differently than you set options for other graphs. While creating an application, use the ActiveX Property Browser to set properties for a 3D graph. Right-click the 3D graph and select Property Browser from the shortcut menu to display the ActiveX Property Browser. If you want to allow users to change common properties at run time or you need to set a property programmatically, use the 3D Graph Properties VIs.
Unlike the graph, which displays new data that overwrites any stored data, the chart updates periodically and maintains a history of the data previously stored. You can customize the chart to match your data display requirements. Options available for all charts include a scroll bar, the scale legend, the graph palette, a digital display, and representation of scales with respect to time. You also can modify the behavior of chart history length, update modes and plot displays.
CONFIGURING CHART HISTORY LENGTH
LabVIEW stores data points already added to the chart in a buffer, or the chart history. The default size for a chart history buffer is 1024 data points. Right-click the chart and select Chart History Length from the shortcut menu to configure the history buffer. You can view previously collected data using the chart scroll bar. Right-click the chart and select Visible Items»X Scrollbar from the shortcut menu to display a scroll bar.
CONFIGURING CHART UPDATE MODES
You can configure how the chart updates to display new data. Right-click the chart and select Advanced»Update Mode from the shortcut menu to set the chart update mode. The chart uses the following modes as shown in the below Figure to display data:
Strip Chart—Shows running data continuously scrolling from left to right across the chart with old data on the left and new data on the right. A strip chart is similar to a paper tape strip chart recorder. The strip chart is the default update mode.
Scope Chart—Shows one item of data, such as a pulse or wave, scrolling partway across the chart from left to right. For each new value, the chart plots the value to the right of the last value. When the plot reaches the right border of the plotting area, LabVIEW erases the plot and begins plotting again from the left border. The retracing display of a scope chart is similar to an oscilloscope.
Sweep Chart—Works similarly to a scope chart except it shows the old data on the right and the new data on the left separated by a vertical line. LabVIEW does not erase the plot in a sweep chart when the plot reaches the right border of the plotting area. A sweep chart is similar to an Electrocardiogram (EKG) display.
The scope chart and sweep chart have retracing displays similar to an oscilloscope. Because retracing a plot requires less overhead, the scope chart and the sweep chart display plots significantly faster than the strip chart.
USING OVERLAID AND STACKED PLOTS
You can display multiple plots on a chart by using a single vertical scale, called overlaid plots, or by using multiple vertical scales, called stacked plots. The below Figure shows examples of overlaid plots and stacked plots. Right-click the chart and select Stack Plots from the shortcut menu to view the chart plots as multiple vertical scales. Right-click the chart and select Overlay Plots to view the chart plots as a single vertical scale.