Global
Use a Global () plot to graph a scalar quantity as a function of time or a parameter. Add Color Expression, Filter, Graph Marker, or Error Bars (Global, Point Graph, and Function) subnodes as needed. Right-click a 1D Plot Group or Polar Plot Group to add this plot type.
Go to Common Results Node Settings for links to information about these sections: Data, Title, and Coloring and Style. Also see the section Expressions and Predefined Quantities.
y-Axis
This section is only available if the Two y-axes check box is selected in the Plot Settings section of the parent 1D Plot Group node’s Settings window.
Select the Plot on secondary y-axis check box to plot the y-axis data on the secondary y-axis to the right of the plot instead of the primary y-axis to the left of the plot.
y-Axis Data (1D Plots) or r-Axis Data (Polar Plots)
For a Global plot, you can plot multiple curves in the same graph using varying line styles and colors. In the table in this section, add one or more expressions to the rows under Expression to define the quantity on the y-axis for each curve, and optionally add descriptions under Description. The descriptions appear in the legends.
For this table of expressions, the Replace Expression and Add Expression buttons have the following effect:
•
Click the Replace Expression () button to select a predefined quantity and replace the entire contents of the Expression table with the corresponding variable as the only expression.
•
Click the Add Expression () button to insert the corresponding variable on a new row in the Expression table.
X-Axis Data (1D Plots) or θ Angle Data (Polar Plots)
From the Parameter list, select an option for what the x-axis represents: Solution number, Frequency spectrum, Phase, or Expression. For Parametric Sweep studies, and when there are multiple inner solutions, Parameter value and Time are available instead of Solution number. Select:
•
Solution number, to use the solution numbers as the x-axis data (or θ angle data for polar plots) for an eigenvalue solution or for a parametric solution with more than one parameter.
•
 Discrete Fourier transform, to display a discrete Fourier transform (DFT) of the data. If you select to display a DFT, choose one of the following options from the Show list:
-
 Real part, to show the real part of the output only.
-
 Imaginary part, to show the imaginary part of the output only.
-
 Amplitude, to show the amplitude of the output (the default).
-
 Phase, to show the phase of the output.
-
 Frequency spectrum, to display the function’s frequency spectrum by computing the number of frequencies and the frequency range based on the FFT (fast Fourier transform) of the function. The transform is valid for all functions, but what you get corresponds to a periodic continuation of the function outside the chosen bounds. To specify these values manually, select the Number of frequencies check box and enter a value in the associated field (the default is based on the number of time samples). From the Scale list, choose None (the default), Multiply by sampling point, or Divide by number of frequencies. You can choose to scale with the sampling period to show Fourier transform values instead of a pure DFT transform. Select the Scale check box to scale the values on the y-axis so that their magnitude reflects the magnitude of the original signal. The values then have the same unit as the input data for the FFT. For a pure sinusoid, the scaled value is the peak magnitude divided by the square root of 2 (). Select the Frequency range check box and then enter the bounds of the frequency range in the Minimum and Maximum fields (in Hz). The FFT algorithm uses resampling based on linear interpolation. The x-axis shows the frequency (in Hz). By default, the y-axis shows the unscaled Fourier coefficients.
If you have selected Amplitude or Frequency spectrum, you can select the In dB check box to present the values in dB. From the dB type list, choose 10log (the default) or 20log. The display in dB requires a reference value. From the dB reference list, choose Maximum (the default) to use the maximum value as the reference, or choose Manual to enter a suitable reference value in the Reference value field.
If you have selected Real part, Imaginary part, Amplitude, or Phase, the following additional settings are available: To specify this value manually, select the Number of uniform samples check box and enter a value in the associated field. If desired, select the Inverse transform check box to use an inverse DFT. Select the Mask DC check box to set the DC value (zero frequency component) to zero (not available if Inverse transform is selected). The Ignore last sample check box is selected by default to not include the last sample in the transform (not available if Inverse transform is selected). The Shift zero frequency and Scale with sampling period check boxes are selected by default. Clear one or more of these check boxes if you want to exclude those steps.
•
 Expression, to specify an expression to use for the x-axis data in the Expression field.
•
Phase, to specify a range of phase angles for the x-axis data. The default for the Phase is (pi/10)*range(0,1,20) (0–360 degrees in steps of π/10 rad). Select a Unit for the phase angle.
•
Parameter value, to use the x-axis data (or θ angle data for polar plots) stored in the solution for a parametric solution with a single parameter.
•
Time, to use time as the x-axis data (or θ angle data for polar plots) for a time-dependent solution.
Parametric Sweep Studies
Under x-Axis Data (θ Angle Data for polar plots), for Parametric Sweep studies, and when there are multiple inner solutions, select an option from the Solutions list: Inner or Outer.
•
If Inner is selected, and for time-dependent studies, the Times steps are plotted on the x-axis and one line per parameter is included in the graph (as listed in the Data>Parameter values section on this page).
•
If Outer is selected, one line in the graph is plotted for each inner solution and the Parameter values are plotted on the x-axis.
One example is a time-dependent problem with a geometric parametric sweep. The time steps are the inner solutions and the swept parameters are the outer solutions.
Quality
This section is only available when the dataset refers to a solution using a time-dependent study. You can then increase the time resolution if needed for a smooth graph plot. In the Refinement list, enter an integer between 1 (the default value) and 1000. For an increased time resolution, enter a higher refinement value.
Legends
The Show legends check box is selected by default to display the plotted expressions to the right of the plot. In plots where each line represents a certain time value, eigenvalue, or parameter value, these values are also displayed.
When Automatic is selected from the Legends list (the default), select or clear the Label, Solution, Description, Expression, and Unit check boxes under Include to control what to include in the automatic legends (by default, it includes the solution and description only). You can also add a prefix or a suffix to the automatic legend text in the Prefix and Suffix fields. If Manual is selected from the Legends list, enter your own legend text into the table. If Evaluated is selected, you can use the eval function to create an evaluated legend text in the Legend field that include evaluated global expressions such as global parameters used in sweeps. For the numerical evaluation, you can control the precision in the Precision field (default: 3).
Small-Signal Analysis, Prestressed Analysis, and Harmonic Perturbation Plot Settings