The Ident Window

Ident is the graphical user interface to the System Identification Toolbox. Within the ident window you can manage all the main activities of the identification process. You can also keep a detailed visual record of the data sets and models you have created. This is achieved by the ident window's menus, pop-up menus and check boxes, as well as by dragging and dropping the model/data icons.

Control actions
You can control the identification session by a number of actions that are all reached from the various controls in this main window:

- The Menus
- The Pop-up menus
- View Window check boxes
- Keyboard hotkeys

Information Management

- The Data and Model boards
- Trash icon
- To Workspace icon
- Status line at the bottom of the window

Selecting Data Sets

- Working Data set icon
- Validation Data set icon

Help topics.

The Ident Window Menus The main Ident window has four menus at the menu bar:

File
  This menu is for session control.
Options
  This menu allows you to create extra model/data boards and to save several settings regarding layout and preferences.
Windows
  This menu gives access to all currently open windows.
Help
  This menu gives various entry points to the help system.

Help topics.

The Ident Window Pop-up Menus The main Ident window has four pop-up menus that control data and model imports, and the creating of new models and data sets. They are labeled as follows:

Data
  This menu allows direct import of data sets.
Model
  This menu allows direct import of models.
Preprocess
  This menu contains several options for creating data sets from the working data by preprocessing, like filtering, detrending, etc.
Estimate
  This menu controls the estimation of models from the working data.

Help topics.

The Ident Window Data and Model Boards The ident window contains 8 (16) positions for data set (model) icons. The view windows show the properties of the selected models and data sets.

Data sets and models are selected by clicking on their icons. Selected objects are marked by a thick line in the icon. Clicking again deselects the object. Any number of objects can be selected at the same time. The icons can be freely moved around by dragging-and-dropping using the mouse. Double-clicking(middle/right mouse button) an icon opens a dialog that provides details about how the data set or model was generated, and also allows you to look at the model parameters (press the Present button).

Extra Data/model boards can be opened as an Option in the ident window. This can be used both to accommodate more models/data sets and to allow a better layout and structure of the created objects.

The contents of the model and data boards (a session) can be saved and reloaded using submenus of the File menu. Data sets and models are deleted by dragging them to the Trash.

Note that data and models do not automatically produce variables in the MATLAB workspace. To apply regular MATLAB commands to them, first export them to the workspace by dragging-and-dropping them on the To Workspace icon.

Help topics.

Working and Validation Data All new data sets and all models are formed from the Working data. This is the data set shown at the center or the ident window. Drag and drop any data set to this position to make it the working data.

All dialogs that depend on the working data will automatically be adjusted to the new set.

The two model views Model Output and Model Residuals are results of applying the model to a certain data set. This data set is the Validaton Data, shown below the model view check boxes inthe ident window. Drag and drop any data set to this position to make it the validation data.

It is good practice to let the validation data be different from the working data, which the model was estimated from. The Quickstart item of the preprocess pop-up menu gives a default split of a data set into working and validation data.

Help topics.

Exporting Data and Models The data sets and models created by ident are normally not MATLAB workspace variables. To further work with them in command line mode, export them to the workspace by dragging and dropping their icon to the To Workspace icon in the ident window.

Note that models are coded into the THETA format, and you work with them with commands like present, th2ff, th2par, th2ss, th2tf, thd2thc, etc. See the manual.

Note also that information about the model or data set is automatically exported along with the variable. It has the same name, with "_info" appended to it. If you import a data variable (using the hotkey d in the ident window) or import a model (using the Model pop-up menu or hotkey m in the ident window) and a corresponding info-variable exist, this will automatically be loaded. Use this if you import back a model or data set.

Example: Export the model `mymodel` to workspace. The do the following commands:
`mycmodel = thd2thc(mymodel); % Transforming it to cont. time.
mycmodel_info = str2mat(mymodel_info,'mycmodel = thd2thc(mymodel)');
% Updating the info variable
` If you now import back mycmodel into ident, it will carry the correct notes and diary.

Help topics.

Deleting Models and Data Sets Delete a model or data set by dragging and dropping it over the Trash Can icon.All plots associated with the variable will then also be deleted.

Double-click on the Trash Can (middle/right mouse button) to open it. Its contents can be dragged back to the data and model boards.

If you empty the Trash can (also an option under the Options menu in the ident window), its contents is permanently deleted.

If you close an extra model/data board that is not empty, its contents will be put in the Trash can.

Help topics.

(file idmw.hlp)