Use a 1D Plot Group () to plot graphs of, for example, a value that varies with time or a frequency spectrum, using options to use FFT with a time-dependent solution. You can also use 1D plot groups to create cross-section plots for solutions in 2D and 3D models. Normally the plot axes (x-axis and y-axis) use linear scaling but, depending on the plotted data, it might be beneficial to display the graphs using a log scale on the x-axis or y-axis. From the Graphics window’s toolbar, click the x-Axis Log Scale () and y-Axis Log Scale () buttons to use a log scale on the x-axis and y-axis, respectively. If you use two y-axes, there is also a Secondary y-Axis Log Scale () button. Click again to return to a linear scale. For a log scale on an axis, COMSOL Multiphysics tries to show values like 10{integer} (for example, 101 or 10−2); if it is not possible to show more than three ticks like 10{integer}, the software instead shows regular numerical values on the axis such as 1, 2, 5,10, 20, 50, 100; and finally, if these regular values are not possible to display, the axes show uniformly distributed regular values. For information about panning and zooming of graph plots in 1D Plot Groups, see Panning and Zooming in 1D Graph Plots.

You can step through time, eigenvalues or eigenfrequencies, or parameter values using the Plot Previous () and Plot Next () buttons at the top of the plot group nodes and their plot nodes. You can also use the F6 and F7 keyboard shortcuts to step to the previous or next solution, respectively. For a parametric sweep with multiple parameters, the buttons step through the innermost parameter only. To move to the solution associated with the first or last time, eigenvalue, or parameter value, click the Plot First () or Plot Last () button. For models with multiple levels of parameters and time, for example, use the list to the right of the Plot Last button to choose the level for which you want to step through the solutions (see Figure 21-5).

The Polar Plot Group node () creates a graph for polar plots: plots of a function in polar coordinates: the radius r and the angle θ. This is useful for visualizing, for example, a radar cross section or other similar polar plots for electromagnetic or acoustic wave models. The available plot types and settings for the Polar Plot Group node are similar to those for the 1D Plot Group.

Select a Dataset. Depending on the type of data, also specify, for example, the time, frequency, or eigenvalue selection. You can also select parameters from parametric sweeps.

For Parametric Sweep studies, also select an option from the Select via list: Stored output times or Interpolated times.

For some solution Datasets, you can select the Load case to use in the plot group (if any load cases exist).

For some Solution datasets, select a Parameter selection (freq): All, First, Last, From list, or Manual.

Select Save plot data to save the plot data in the model. This section only appears for the manual setting of the option for saving plot data. See Saving Plot Data in the Model.

The Title type is automatically generated by default (the Automatic option). Select Custom, Manual, Label, or None as needed. See Plot Titles for Plot Groups and Plot Types for more information.

From the Color list, choose Custom to define a custom color for the title, or choose one of the predefined colors (the default is Black).

Manually enter axis labels by selecting the x-axis label and y-axis label check boxes for 1D plot groups.

If you have more than one plot in the plot group, you can use two y-axes. Select the Two y-axes check box to add a secondary y-axis to the right of the plot. Then you can also select the Secondary y-axis label check box to add a label for that y-axis in the associated text field. At the bottom of this section, a list of all graph plot and annotation nodes under this plot group that can use the secondary y-axis appears. In the Plot on secondary y-axis column, select the check boxes for the plots and annotations that you want to plot on the secondary y-axis. You can also specify that a plot should use the secondary y-axis in each plot’s Settings window’s y-Axis section, where you can select or clear the Plot on secondary y-axis check box.

Select the Flip the x- and y-axes check box in cases where flipping the data for the axes may provide a better visualization. Switching the data also switches the axis labels if they are not specified manually.

Select the Manual axis limits check box to edit the limits already assigned based on the dataset. For 1D plot groups, this is for the x minimum, x maximum, y minimum, and y maximum. If the plot uses two y-axes, you can also specify the Secondary y minimum and Secondary y maximum. For Polar Plot Groups, this is for the r minimum and r maximum. Additionally, for Polar Plot Groups, the following settings are available:

For the 1D Plot Group, and as needed, select the following check boxes: Preserve aspect ratio, x-axis log scale, and y-axis log scale. If the plot uses two y-axes, you can also select the Secondary y-axis log scale check box. Select the Preserve aspect ratio check box to preserve aspect ratio and keep the distances on the x-axis and y-axis equal. The second part is not possible to achieve if one of the y-axes uses a log scale. However, the first part stays active; that is, if you zoom on one of the axes, all of the axes will be equally transformed (scaled).

Clear the Show grid check box if you do not want to include a grid in the plot.

Select the Manual spacing check box to edit the fields. For 1D plot groups, this is for the x spacing and y spacing fields. For Polar Plot Groups, this is for the r spacing and θ spacing (SI unit: degrees) fields.

For 1D plot groups, also specify extra grid points on the x-axis and y-axis in the Extra x and Extra y fields. If the plot uses two y-axes, you can also add extra grid points for the secondary y-axis in the Secondary extra y field. For Polar plot groups, this is for the Extra θ and Extra r fields.

Select the Show legends check box to display legends for the quantities in the graph and, if using a Color Expression subnode, color legends.

Specify the position of the graph legends for the plots in the plot group. From the Layout list, choose Inside graph axis area (the default) to show the legends within the graph plot limits, or choose Outside graph axis area to show them outside of the graph plot limits. From the Position list, when Inside graph axis area has been selected, select Upper right () (the default), Upper middle (), Upper left (), Middle right (), Center (), Middle left (), Lower right (), Lower middle (), Lower left (), or Manual. If you choose Manual, define the relative position (0–1) in the x-position and y-position fields. If Outside graph axis area was selected, choose Bottom (), Left (), Right () (the default), or Top (). Also, if the desired, you can specify to display the legends using a number of columns or rows (depending on the position) in the Number of columns or Number of rows (only for Bottom and Top when Outside graph axis area was selected) field (default: 1).

For color legends, select or clear the Show maximum and minimum values check box to show or hide those values from the top and bottom of the color legends. Also select the Show units check box to display a unit above the color legend, if desired.

Specify the location of the color legends (color scales) for the plots for this plot group. The Position list contains the following positions for the color legends:

To override the automatic formatting of the numbers on the axes, select the Manual axis settings check box. Then adjust the formatting using the following settings:

From the Notation list, choose Automatic to let the program choose decimal notation or scientific notation (E-notation) depending on the values of the displayed numbers. Choose Scientific to only use scientific notation.

Select the Use common exponent check box (selected by default) to use a common exponent at the end of each axis. Clear this check box to instead display the full numbers, including the exponents, next to the corresponding axis tick. One of these formats may be better suited to display the axes if the plot window is small, for example.

Select the Show trailing exponent check box to display all numbers based on the precision used, including trailing zeros (for example, 5 is then displayed as 5.000 when the precision is set to 4).

In the Precision field, enter a positive integer (default: 5) for the numerical precision (number of digits displayed).

Select a Plot window. The Graphics window is the default, but any other plot window can be selected, or select New window to plot in a new window. Select the Window title check box to enter a custom title (except for the Graphics window), which is then available in the Plot window list for all models. Click the Add Plot Window button () to add a plot window to the list of available windows.

Use a combination of datasets and plots to create a cross-section point plot and cross-section line plot. To add plots to a group, right-click the 1D Plot Group node to select as many as needed. Each plot group can have several plots combined to create a meaningful representation of the data.