Differences

This shows you the differences between two versions of the page.

--- poliflows:gui [2015/09/04 11:49] – created cerquaglia
+++ poliflows:gui [2019/05/07 13:23] (current) – removed boman
@@ Line 1: / Line 1: @@
-POL(I)FLOWS disposes of a very simple graphic user interface, called `viewer`, whose main purpose is to provide real time information about the simulation.
-In the following we explain very briefly how viewer looks like, how to interact with it and how to activate or deactivate it (note that the use of the graphic interface obviously slows down the simulation a little bit).
-## How the POL(I)FLOWS-GUI looks like
-If the GUI option is activated, when we run the simulation, the GUI opens, and looks something like this:
-![alt text](https://cloud.githubusercontent.com/assets/7070237/9202112/88374722-4050-11e5-85a1-9752abcb5fb9.png "Viewer before running")
-You will notice that there are two main areas:
-* the **results window** (the main window);
-* the **interaction panel** (in grey, on the right).
-In the **results window**, the real time evolution of the problem is shown. Usually the mesh, the nodes and a scalar field are visualized. The field values are reported on a scalar bar on the bottom of the window.
-**NB**: for the moment the only scalar field to be visualized is the pressure field, and unfortunately it is impossible to change this option unless by modifying the source code. Nevertheless, velocity fields (x-component, y-component, euclidean norm and vector) are included in the `.res` results and can therefore be visualized in the post-processing phase using Gmsh (see e.g. the [[Results gathering and post-processing|https://github.com/mlucio89/PFEM/wiki/Flowchart#results-gathering-and-post-processing]] section).
-The **interaction panel** allows the user interact with the GUI in some simple ways.
-## How to interact with the POL(I)FLOWS-GUI
-The interaction panel is the way the user can interact with the viewer, even if just in a very simple way at this stage.
-If we look at the interaction panel, five main interactions can be identified, as highlighted in the picture below:
-![](https://cloud.githubusercontent.com/assets/7070237/9202460/3bde4d2e-4052-11e5-9403-afaaf4db2643.png)
-In the following a brief decription of each interaction is provided.
-### 1 - The start/stop button
-The start/stop button is used, as the name suggests, to start the simulation and to stop it once the computation is over, but also to pause and restart the simulation on the fly!
-### 2 - Fixing the scalar bar
-In the `Scale` panel, you can decide whether or not fixing the boundary values of the scalar bar and choose these values.
-In general, it is suitable to fix the scalar bar, since otherwise, due to the fact that it adapts itself to the results, one could observe sudden changes in the field colors which make the physical interpretation of the results more difficult. As an example, let us consider the two pictures below.
-* the scalar bar is not fixed:
-![alt text](https://cloud.githubusercontent.com/assets/7070237/9219748/576ce74a-40dd-11e5-9967-5ba9a4459167.png "Scalar bar not fixed")
-* the scalar bar is fixed:
-![alt text](https://cloud.githubusercontent.com/assets/7070237/9219749/57878834-40dd-11e5-9e85-d1b322636bd0.png "Scalar bar fixed")
-Both of them show the pressure fields in a coloumn of water in a dam break problem, at two subsequent time instants: in the first case the scalar bar is not fixed, while in the second it is.
-You can easily appreciate the fact that the second result is much more easy to interpret than the first one!
-### 3 - The 'verbose' option
-The `verbose` option provides the user with some additional information on the simulation.
-For the moment, for example, if this option is activated, the relative error (in percentage) on the mass conservation is plot on the command window at the end of each time step.
-### 4 - The 'Infos' panel
-The `Infos` panel provides the iser with some very basic information on the simulation, which are, at the moment, the _step_ number and the current _time_ of the simulation.
-### 5 - Visualizing Voronoi cells
-In the Particle-Finite Element Method, Voronoi cells are, or could be, employed in many ways. Therefore, it can be useful to visualize their evolution as the computation evolves: this is what the `visualize Voronoi cells` option has been introduced for.
-If the `visualize Voronoi cells` option is activated you will observe something like this appearing:
-![alt text](https://cloud.githubusercontent.com/assets/7070237/9220530/8efb89fe-40e3-11e5-920d-06c1e0ea1a59.png "Voronoi cells visualization")
-Voronoi cells are represented in white.
-**NB**: the definition of the Voronoi cells implies some additional computations, that is why they are not created unless the user asks for it explicitly, by activating the `useVoronoiCells` option in `w.Msh` (see [[Geometry and mesh import|https://github.com/mlucio89/PFEM/wiki/Input-file#geometry-and-mesh-import]] section). If the `useVoronoiCells` option is not activated, while `visualize Voronoi cells` is, the cells are obviously not visualized, the simulation does not stop, but a warning message is shown at the end of each time step, until the `visualize Voronoi cells` option is deactivated.
-## Activate and deactivate the POL(I)FLOWS-GUI
-In order to launch the GUI some simple instructions have to be added at the [[end of the input file|https://github.com/mlucio89/PFEM/wiki/Input-file#input-file-end]]:
-```python
-usegui=1
-if not usegui:
-    scheme.start()
-else:
-    gui = v.MeshViewer(msh, scheme)
-    gui.start()
-```
-**NB**: the definition of the `usegui` variable is not necessary, but it is useful, since you can activate and deactivate the graphic interface, just by setting its value to 1 or 0.