====== Expression editing tool ======

The editor tool appears when a table cell is clicked that contains an expression. It can be hidden by clicking the **Toggle** button, as shown in the screen shot below.

{{expression_edit_tool.png?600|Editting window}}

The equation editor is very useful when your [[Model|model]] contains a large number of blocks as it allow you to quickly find either existing blocks.

Next columns are presented in the **Editor** (equation editor)


 **Item** – presents the name of block or function.

 **Value** –  in case of blocks presents Value. 

 **Unit**  –  in case of blocks presents the unit of block.

 **Full name** – in case of blocks presents the Full name of block. In case of function the name of function is presented. 

 **Description** – presents the description of function in case of functions and description of block (if it is able). 

 **Type** – in case of block shows type of block (Compartment, Expression etc.) and in case of function type is functions. 

Presents the list of all available in Ecolego [[Function|functions]] with short description as well all presented blocks in the model (except [[connector]|connectors]], [[model_input]|inputs]] and [[model_output]|outputs]]). Also, in the list are presented [[index_list|indecies]].

A list of all available objects that can be used in equations, for instance [[Compartment|compartments]], [[Expression|expressions]] and [[Parameter|parameters]]. This list also includes all entries in the [[Glossary|glossary]], all blocks available in the [[Parameter_database_toolbox|parameter database]] and all [[Function|functions]].

===== Auto completion =====

While you enter an expression you can press the **Space** key on your keyboard to quickly find names of objects in the model or in the [[Parameter_database_toolbox|parameter database]]. If you are writing the expression “rate//Co//” and press space, all objects that contain the text “Co” will be displayed. You can use the arrow-down key to select one of the listed names, and return to select it.

====== Tools ======

The editor contains several tools at your disposal. By using the buttons in the toolbar you can select which tools to show.

==== Show/Hide calculation tool ====

|Note|For more information about conditions see [[Expression_syntax|expression syntax]]|

When this button is enabled operators are added to the table in the *Editor*. They are added under the list of all presented in the model blocks.
Use the keypad with the mouse to enter a value or an operator without having to use the keyboard.

==== Show/Hide the list of available blocks ====

When this button is enabled all available [[block|blocks]] in the model are added to the list in the table in the *Editor*. 

Local objects, that is, objects from the same [[Sub-system|Sub-system]] as the currently edited object, are highlighted in **bold**.
==== Show/Hide the list of available functions ====

|Note|For more information about functions see [[function|function]]|

When this button is enabled list of functions is added to the table in the *Editor*. 

====  Functions ====

|Note|The time function included in the functions list can be used to insert time-dependent conditions in equations.|

The functions list contains a list of the available [[Function|functions]] in Ecolego. If you want to add your own [[Function|functions]] to the list, please see [[Creating_custom_functions|creating custom functions]]).

====  Show/hide database name tool ====

|Note|To use this option user should be logged-in into the [[Parameter_database_toolbox|parameter database ]]|

When this button is enabled all available parameters from parameter database are added to the list in the table in the *Editor*. 


===== See also =====

  * [[Automatic_object_creation|Automatic object creation]]

  * [[Expression_syntax|Expression syntax]]