Engee documentation

Graphs

The Charts window graphs icon 1 is one of the main tools for visualising Engee signals.

The graph window displays only recordable signal logging 1 signals. To enable recording, select the option Log:

graph logging 1

Visualising simulation results helps to understand and tune the behaviour of the model. Engee allows you to visualise results in the following ways:

More Engee visualisation tools are available in the section Other Engee visualisation tools.

Graphs and coordinate planes are used to work with graphs and coordinate planes Graph window tools.

The resulting graphs can be easily exported (Graph export) in PNG or CSV format.

For convenient work with the graph window you can:

  • Expand/compress graphs horizontally and vertically:

    graph compression

  • Compress the coordinate plane vertically:

    graph compression 1

  • Clamp a signal name and transfer it to the graph (to specify a signal name, double-click on it and enter the desired name):

    graph compression 2

  • Work with signals from the same simulation on different coordinate planes. To do this, press the button Add chart add graph button and select the desired signal and its display type.

Signals in the time domain signal graph 1

Create a model using the Sine Wave Function and Terminator blocks, and enable recording of signal logging 1 signals between them. Leave all parameters and settings by default. The final model will look like this:

graph beginning 1

Run the simulation with the button Start start simulation button. The graph of the sinusoidal signal simulation will be displayed in the graph window graphs icon 1 on the coordinate plane. Before the graph is displayed, you can select the type of signal display and the signal itself:

prework log sim settings graph

Select the type Time Domain Signals signal graph 1 and Sine Wave.1 signal to get a graph of a sine wave:

graph explaination

Signals in the frequency domain signal graph 2

If the frequency domain signal graph signal graph 2 is not displayed, the system does not have enough data. A minimum of 1536 data points are required to plot the graph. This number is calculated using the formula:

The minimum number of points required is calculated based on Henning window function. To get the required number of points, you can either increase the Simulation time or decrease the Sample time. The formula applies to both Time Based and Sample Based blocks.

The graph in the frequency domain represents the spectrum of the signal, showing which frequencies are present in that signal. Create a model using the Pulse Generator and Terminator blocks. Leave parameters and settings by default and enable recording of signal logging 1 signals between blocks:

pulse generator model new

Specify a simulation time of at least 16 seconds (otherwise there will not be enough data points) and start the simulation with the button Start start simulation button. After the simulation, open the graph window graphs icon 1 and select the display type Frequency domain signals signal graph 2.

After saving you will get the spectrum of the block signal Pulse Generator:

pulse gen freq graph 3

Additional settings of the spectrum of the model signals are available using Spectroanalyser of the graph window. To do this:

The dependence of one signal on another signal graph 3

Create two models from blocks Sine Wave Function and Terminator, and enable recording of signal logging 1 signals between them. Leave all parameters of the blocks and model settings by default, but for the Sine Wave-1 block increase the frequency (Frequency) from 1 to 2.

For clarity, name the signals - double click on the signal from the Sine Wave Function block and name it x, and for Sine Wave-1 block name it y. The final model will look like this:

sine wave model example 2

Run the simulation with the button Start start simulation button. In the graphs window, select the display type Dependence of one signal on another signal graph 3 to open the signal selection window. Select x for the x signal and y for the y signal, respectively:

signal choosing 1

The result is the following graph (Lissajous figure):

graph lissajous curve 1

The graphs can also be compared in the time domain signal graph 1. Use the same model. In the graph window, use the button Signal Menu signal menu 1 switch to Time Domain Signals signal graph 1 and select both signals.

Move the mouse cursor over the coordinate plane - this will bring up the graphing tools:

signal comparison 2

In the new coordinate plane, move the mouse cursor over the coordinate plane again and display the tools, select Two cursors signal comparison 1. Select the desired point on the graph and compare the signal values with each other:

signal comparison 3

Signals in tabular form signal graph 4

Assemble the following model from the blocks Sine Wave Function, Constant, Identity Matrix and Terminator:

table graph 1

Start the simulation with the button Start start simulation button. After the simulation, select the type Signals in tabular form signal graph 4. A table with instantaneous values of signals will open in the graph window:

img sim 15 4

To switch to other display types, use pen button graphs.

Frame in time domain frame based icon 1

Time domain frame frame based icon 1 - the model processes several data items in one time step. For more information about frame-by-frame signal processing in Engee, see the article Signal processing by frames and samples.

Signal constellation signal constellation

Constellation diagram signal constellation (or constellation diagram) is a graphical method of representing modulated signals in digital communication. It is used to visualise the symbols transmitted in a modulated signal and helps to analyse the quality of data transmission and detect distortions. Read more in the article Signalling constellations.

Array construction massive icon

Array plot massive icon - is the process of visualising data organised into arrays on graphs. It allows you to interpret numerical data as functions of time or other variables, displaying them as continuous lines and points:

massive graph 1

Eye diagram eye diagramm 1

Eye diagram eye diagramm 1 - is a tool for analysing digital signals to help detect errors and distortions in data transmission. It displays repeatedly superimposed time sections of a signal, creating an eye-like image. This allows you to visualise signal distortions such as: intersymbol interference (ISI), noise, duty cycle distortion and other interference.

An important advantage of the eye diagram is the ability to assess the quality of data transmission by the width and shape of the "eye" - the more open the "eye" is, the better the signal transmission.

glass diagramm 2

The diagram is used to analyse noisy signals to understand how well the data is being transmitted over the communication channel. For example, an eye diagram helps to identify deviations from an ideal signal caused by factors such as frequency offsets or phase errors.

Intensity diagram intensivity diag

Intensity Scope - is a visualisation tool used to show the distribution of signal power or amplitude as a function of coordinates or time parameters. It helps to analyse changes in signal intensity at different points in space or time, which is particularly useful in radar and DSP.

An intensity diagram allows you to visualise how the energy of a signal is distributed in the area under study. For example, in optical systems, it helps to analyse the distribution of light in a beam, and to detect focusing and divergence of beams. In radio engineering and acoustics, it is used to study the directionality of radiation and signal levels in different directions.

image3

Graph window tools

Depending on the type of signal display, different graphs useful for individual situations are obtained. But this is only a part of the functionality of the charts window. Further we will consider the toolbar and its capabilities.

To view the available tools of the charts window graphs icon 1, move the mouse cursor over the coordinate plane. Two sets of tools are available in total:

img15a

Overview of chart window tools

First set

Second set

The first set contains everything you need to work with charts:

img15a 1

  1. Signal Menu - menu for navigating between coordinate planes.

  2. Zoom - scales the coordinate plane. You can select an area and zoom in on its contents. To restore the scale by default, double-click the coordinate plane with the left mouse button.

  3. Pan - tool for moving the chart on the coordinate plane. Allows you to move the chart in any direction using the mouse cursor.

  4. Zoom in - zooms the coordinate plane.

  5. Zoom out - zooms out the coordinate plane.

  6. Autoscale - returns the coordinate plane scale value by default.

  7. Download plot as a png - saves the coordinate plane to a PNG file.

  8. One cursor - displays values on the chart when the mouse pointer is hovered over it.

  9. Two cursors - displays values on all charts.

  10. Settings - opens the graphs and coordinate plane settings. Graph settings consists of three sections:

    • Plot and axis - Graphs and Coordinate Plane Display Control section:

      menu settings 1

    • Signals - section of signal display control. Signal control is available when a specific signal is selected on the coordinate plane of the graph window graphs icon 1.

      graphs signal settings

    • Spectrum analyzer - section of additional spectrum setting (for details see the article Spectrum analyser). The section is available when the signal display type "Signals in the frequency domain signal graph 2".

      spector analyzer 1

The second set is designed to work with two or more coordinate planes:

img15b

  1. Up - moves the coordinate plane to the cell above.

  2. Down - moves the coordinate plane to the cell below.

  3. Copy - copies the coordinate plane. Does not copy to the clipboard, you cannot paste the copied coordinate plane anywhere other than the chart window. The copied plane can only be pasted via the button Paste img 15 1 4.

  4. Paste - pastes the copied coordinate plane.

  5. Copy to clipboard - copies the coordinate plane to the clipboard. You can paste the plane into Engee and other third-party programmes.

  6. Delete - deletes the plane.

Button Delete delete button graphs button will automatically appear in the action bar when a new coordinate plane is added.

To add a new coordinate plane, use the Add chart add graph button. This button will allow you to configure the plane before it is added and will re-display the menu of signal output and display types. The new plane will be added above the old one by default. You can change their order using the tools.

To add a new tab in the chart window, use the button New tab new tab graph button button and give it a name. In the created tab you can work with new or existing simulation results in the usual mode.

img 15 1 2

The tabs can be arranged vertically for convenience:

vertical tabs 1 -> vertical tabs 2

Graph export

Three methods are available for exporting the graph:

  • Save the coordinate plane as an image using the button Download plot as a png save as png button. The image will be automatically downloaded to your computer at the path specified in your operating system.

  • Insert the coordinate plane image into Engee and third-party programmes using the button Copy to clipboard clipboard copy 1.

  • You cannot export the plot to CSV directly, but you can export its signal data using the To CSV block. To do this, put the block To CSV on the output of the desired model signal and in the parameters of the block specify the name of the future CSV-file. File name block parameter, specify the name of the future CSV file (untitled.csv by default). The CSV file will be saved in file browser Engee under the specified name.

Other Engee visualisation tools

If your visualisation tasks are much broader than described in the previous sections, Engee offers you other tools. Check them out to find the best solution for visualising the results of your models:

  • Data Inspector allows you to view, analyse and compare the results of both single and multiple simulations (runs).

  • Variable simout allows you to work with the results of a model simulation via the command line or script editor, for example, using the library Plots.