Tutorial

Exploitation of results and access to the data

This tutorial explains how to access the data stored in files during a simulation and how to exploit the results.

1) The storage files

2) Maps

__2.1. View the main results directly as 3D maps.

__2.2. Change the legend

__2.3. Visualize the fluxes

__2.4. Search for a specific value

__2.5. Looking at a particular place

3) Access to the complete set of data: time series

4) Time graph

1) The storage files

The results of a simulation can be stored in files at regular intervals (see 'Main steps of a simulation' tutorial. These files can't be read outside of the LASER/F interface. They are binary files and have * .reb extension. By convention their name begins with a generic text 'yyy' followed by two numerical parts. In the example 'Rue25-20160701-100000.reb', the generic text is 'Rue25'. You are free to give any generic text, provided that it is as short as possible, made up of letters or numbers and without special characters (+, -, /, ...). The minus sign (-) has a special meaning: it serves as a separation between the generic text, the date and the time parts. In the example above '20160707' gives the date in the following order: year (2016), the month (07), day (01). '100000' indicates the time (UTC) in the following order: hour (10), minutes (00), seconds (00). The date and time correspond to the time step which was simulated and this part is automatically created by LASER/F. This convention guarantees that the files are correctly sorted in the order of the time steps which were simulated.

If you want to exploit a simulation you have conducted with LASER/F you need to load data from a file into memory.

In the menu bar of the 'Main' form, > 'Résultats' > 'Exploiter une simulation',
Make sure you are in the directory where you requested to store the results. In the list of * .reb files, choose a file among all those whose name starts with the generic name you are interested in (e.g. 'Rue25-20160701-100000.reb) > 'Ouvrir',

The data simulated for the timestep july 1, 2016 at 10 UTC can now be visualized

2) Maps

__2.1. View the main results directly as 3D maps.

Click on the 'Visualisation' page.
In the groupbox 'Résultats', 'Sélection principale' check the result you want to visualize:
'Temp. surface' for example if you want to see the surface temperatures. The choices in this groupbox are mutually exclusive.
Now activate the 'Visualisation' form to access the viewer and see the results in 3D,
Use the set of buttons at the right bottom of the viewer to move forward or backward in time (this will also change the active *.reb file)

3D maps

__2.2. Change the legend

Modify the max., min. and colors of the legend:

'Visualisation' form
click on the 'Légende' groupbox located on the left of the viewer, a new little form entitled 'Légende' will open,
modify the min. and max. value and uncheck 'min. et max. auto' to introduce manually your own extreme values. When 'min. et max. auto' is checked, these values are automatically set,
Modify the colors attributed to the max. and min. values: click on the colored buttons and choose your color,
Reinitialisation to default values can be done with > 'Reinitialisation'.
> 'OK'

Warning: if you manually modify the min. and max. of the legend, it may be that when you change for another variable, the scale is no longer adapted to the new values!

__2.3. Visualize the fluxes

To visualize the components of the energy balance,

'Sélection principale' > check 'Flux'
check one variable in the 'Flux' groupbox. Warning: these variables can be added all together, for example it is possible to check simultaneously 'Direct' and 'Diffus' to visualise the solar global radiation. The fluxes are all expressed in W/m².

The viewer is automatically updated.

__2.4. Search for a specific value

It is possible to find a specific value on the map, for example to see the location of the min. or the max.. Be sure this value exists in the results. If it exists several times, only the first occurrence will be shown.

'Main' form > 'Visualisation' page
Type the value you want to find in the white label entitled 'Chercher une valeur' > 'Chercher'. The first mesh with the desired value has been selected
go to the 'Visualisation' form > 'Options de visualisation' groupox > check 'Axes/nord', this will center the axis system on the mesh. Convention: Red axis for east-west direction, green axis for north-south direction and blue axit for vertical. The solid white line indicates the position of the sun.

__2.5. Looking at a particular place

To look at a particular place there are three methods.

Method 1:

'Visualisation' form,
Move your mouse over the viewer,
Choose a point on the scene by right-clicking on any coloured object ,
Zoom in or out the 3D scene with the wheel,
Rotate around a selected point by keeping the left mouse button pressed and move.
Rotate the scene with the arrows of the NUMERIC KEYPAD: left, right, top, down

Some basic information are displayed in the groupbox 'Info' in the lower part of the 'Visualisation' form.

Method 2:
A list of objects is also available in the treeview located in the upper left part of the form. You can choose any object in the list by clicking on it. Each object is identified with a unique number and name stored in the 'construction.geo' file.

Method 3:
Specify manually the sight settings

'Main' form > 'Visualisation' page
specify the position of the viewer 'Observateur' and the target 'Cible' with their tridimensional coordinates > 'Executer'

3) Access to the complete set of data: time series

To access the data stored during a simulation in the *.reb files and obtain time series:

In the menu bar of the 'Main' form, > 'Résultats' > 'Exploiter une simulation',
Make sure you are in the directory where you requested to store the results. In the list of * .reb files, choose a file among all those whose name starts with the generic name you are interested in (e.g. 'Rue25-20160701-100000.reb) > 'Ouvrir',
'Visualisation form', click with the right button of the mouse on a place of the simulation scene which is displayed in the viewer
Return to the 'Main' form and activate the 'Diagnostiques' page. This page gives you the possibility to display your data in tables.
In the checklist box located at the bottom left of the page, check 'Mesh sélectionnée' for example
In the toolbar click on > 'Toute la série' and on > 'Actualiser affichage'. All the useful calculated data for the selected mesh are now displayed in the table from the beginning to the end of the simulation.
In the same way, you can obtain the average data calculated for a face, an object, an atmospheric voxel or the entire scene

You can copy the complete set of data in the clipboard to paste them in any software (excel for example)

Click on 'Copier: tout' > open your software and paste the data

Spreadsheets

4) Time graph

There is the possibility of directly making a time graph. This possibility was introduced only for the purpose of getting a quick first overview. Use specialized software to get cleaner graphics.

In the toolbar click on > 'Graphique'. This will open a new forme,
In the checklist box located on the left, check the variable you want to display
Up to 10 variables can be displayed at the same time.

Time graph

Additional information is available in the next tutorial on the detailed meaning of the variables obtained as output of the model, as well as on some useful urban descriptors that can be calculated with LASER/F.