ParaView/Users Guide/Plotting and Probing Data

There are multiple ways of probing a data set for point or cell values. The simplest is the Probe Location filter. Additionally, there are a variety of filters to plot data with respect to time, location, or grid object Id.

Probe Filter

The probe filter can be used to query a data set for point or cell data.

Options for the probe filter are:

• Show point button is used to show where the center of the sphere is for generating the probe points.
• Center on bounds will place the sphere center at the center of the data set's bounds.
• The sphere center can either be set in the properties tab of the object inspector or in the 3d view with the mouse cursor. To choose a new point in the 3d view window, press P and then click on the desired point. Note that the Show Point option must be selected in order to activate the point widget.

The output for this filter is a single cell comprised of a set of points in a vtkPolyData.

Line Plots

The line plots have similar control functionality for displaying the results. These options are in the Display tab of the Object Inspector and include selecting which point and/or cell data to include in the plot, what should be used as the x axis values (e.g. point/cell index or a specified point or cell data array), and plot preferences such as line thickness and marker style.

Plot Data / Scatter Plot

The Plot Data filter and Scatter Plot filter are very similar in functionality with the Scatter Plot filter being a deprecated version of the Plot Data filter. The main difference is that the Scatter Plot filter's output is a 1D rectilinear grid while the Plot Data filter's output is the same type as the input.

The Plot Data filter plots point or cell data over the entire data set. By default the x axis values are determined with respect to their point or cell index.

Plot Over Line

The Plot Over Line filter is used to plot point data over a specified straight line. The Plot Over Line filter will not display cell data over the line so the user can use the Cell Data to Point Data filter to convert cell data to point data in order to use this filter for viewing desired cell data. The line geometry can specified either by setting the points in the Properties tab of the Object Inspector or by pressing P and selecting the beginning and ending points of the line. Note that the Show Line option must be selected to activate the line widget. The resolution option is used to specify at how many evenly spaced points on the line to query the data set for information the point data to plot with respect to.

Plot on Sorted Lines

The Plot on Sorted Lines filter is used when polydata with line cell types have been extracted from a data set and the user wants to see how point data varies over the line. This filter orders the lines by their connectivity instead of their point index.