Using the software

Basic usage

Spintronics-visual has some features that help you visualise the magnetic layers.

Loading directories

As you open the app, you'll see a large button 'Add Widget' in the middle of the screen. If you have not loaded any data, then this button will prompt you to do so - simply select a directory.

Directory must contain both .odt and .omf files (there should be just one .odt file in the selected directory, but there can by plenty of .omf files).

OpenGL

We use OpenGL framework to render 3D objects representing magnetic layers. You can add two types of OpenGL widgets for now: CUBIC, ARROW and VECTOR. The first one will draw cubic objects, the second, high quality arrows and the third - vectors (representing magnetisation vectors). Attempting to add any of these would prompt a settings menu. There you can specify:

• Averaging - this reduces the number of vectors by sampling randomly - decreases computational complexity, use when your machine is not really powerful,
• Decimation - takes every n'th vector and then compensates for doing so by enlarging the leftover objects,
• Layers - you can select which layer to display, or all of them,
• Color settings - R, G, B - will determine the mixture of the color as a dot product. For example: the vector specified at R will increase the amount of red color as the dot product of that vector with any of the magnetisation vector will increase. Analogously, green would increase as magnetisation aligns itself with the green vector and so on.

2D plotting

You can specify two types of 2D plots that display time-dependent series in .odt files. They can be used along 3D plot as well. There are:

• 2D Matplotlib engine plot
• 2D OpenGL engine plot

Matplotlib is generally better-looking but much slower and has more features. However, if you require speed, go for 2D OpenGl engine plots. Adding any of these widgets to widget pane, will prompt a style menu - pick a column from .odt file to display and specify some styling options.

There is also a third 2D plot option:

• 2D Layer

2D Layer plots a selected layer on the 2D surface where a colour of the pixel is determined according to the dot product performed on the picked relative vector. Uses Matplotlib engine, thus it is not recommended to use with multiple windows on a greater display speed.

Recording

To start a recording and pause it, use a start/stop recording button or key. In order to specify a location when screenshots will be saved, go to Options->Frame directory. When you have saved all the screenshots and are interested in composing a movie out of them, then go again to Options->Movie composer and select a directory with screenshots that are to be merged into a film. Please note that you have to have ffmpeg software to run this. On Linux it can be installed from the repositories, but on Windows you must fetch it from the internet, for example here.

Key shortcuts in OpenGL contexts

Some of the shortcuts are visible in toolbar (since v.0.6-alpha)

• I - zoom in function.
• O - zoom out function.
• R - Reset function - reset all camera and object changes to default state.
• Y - start/stop recording.
• S - take a Screenshot of a current frame.