ANY-maze Help > The ANY-maze reference > The Protocol page > The elements of a protocol > Testing > Procedures > Elements of a procedure > Variables available to procedures > Built-in variables

Built-in variables

Introduction

Built-in variables are a way for a procedure to be able to ask the ANY-maze software about anything to do with the state of the current test. They can be anything from a simple flag specifying whether the test is currently running, to the animal's current position, to a note of how many times the animal has entered a specific zone.

There are many of these built-in variables available in the ANY-maze procedure system, and they are listed below. You can also see what is available by expanding all the groups in the Variables tab of the procedure editor. Variables are available for the apparatus itself, as well as for all relevant items in the protocol list - zones, animal activity, key presses, I/O, etc. Hovering over the relevant variable will show a tool tip to give you more information on that variable.

When the procedure editor is in 'Simple' mode, the Variables tab is not shown. You can switch the procedure editor between Simple view and Full view using the buttons on the ribbon bar.

Built-in variables are available to a procedure for a number of aspects of the test:

More information

Built-in variables can only be read by a procedure, and not changed, so you can't use a Set value statement to alter the value of a built-in variable.

They can be one of a number of types - this is visible from the shape of the variable in the list in the procedure editor. Shapes with angled edges are True/False values, shapes with rounded edges are numeric values, and squares with cut-off corners are ANY-maze protocol items as set up in the protocol list (e.g. zones, sequences, etc.).

Figure 1. The test information built-in variables, showing their different shapes. Test is running is a True/False value; Current trial, Test duration and Number of trials are numeric values, and Current stage and Treatment are ANY-maze protocol items as set up in the protocol list.

You can use a built-in variable anywhere in a procedure where an expression of the variable's type can be used - for example, in a Maths function or operator, a logical operator, or to set as the new value for a User-defined variable.

The built-in variables available are listed below:

Test information

If the treatment's value has not yet been set, this will return '#N/A'.

Test date/time

Animal position and movement

Note that the Animal is active variable is only included for legacy reasons and is not available to be included in new procedures. Activity depends on a number of separate conditions - for example, whether the animal is mobile, or a key is pressed that counts as an activity. However, immobility cannot be detected immediately - there is a 'timeout period' specified, and until the end of that timeout, the system doesn't know that the animal has gone immobile (so the current state is still 'mobile' until the end of the timeout). Even though the animal has actually stopped moving (but the system hasn't yet detected it), during this timeout period something else - such as a keypress - might indicate the animal being active. But because the system has not yet detected the inactive state (it still thinks the animal is mobile), it effectively 'misses' the activity keypress and therefore does not hold the correct active state. (Note that activity can still be calculated during result analysis, because at that point the system has a full history of exactly what happened at every point during the test).

Zone variables

If the location of the zone has not yet been set, this will return '#N/A'.

Point variables

Stage and trial variables

Sequence variables

Key variables

On/off input variables

Signal input variables

Note that Signal input values that are passed to a procedure are limited to a sample rate of 100Hz; if the signal's sample rate is greater than this, then using this built-in variable to read the signal's current value may miss transient peaks of the signal.

Sensor variables

Rotary encoder variables

Output switch variables

Speaker variables

Pellet dispenser variables

Analogue output variables

Temperature controller variables

Light controller variables

Syringe pump variables

Shocker variables

Laser controller variables

Selector variables

Selectors are only available on certain types of device (such as the ANY-maze Operant interface and Ugo Basile Operon).

Although the current value of a selector is returned as a protocol item, it can also be evaluated as a numeric value. If the current value of the selector is copied into a user-defined variable, then it will be stored as a numeric value. This doesn't cause any problems with other parts of the procedure, because selector values can be set as either a protocol item or a numeric value.

Field variables

If the field's value has not yet been set, this will return '#N/A'.

Virtual switch variables

ANY-maze protocol items

Some of the variables listed above return one of a list of 'known values' from the protocol as a return value. For example, the direction of a syringe pump is always 'Infuse' or 'Withdraw', and the location of a movable zone can only be one of a set of predefined locations.

All of the possible values of these, and anything else defined in the protocol, are listed under the ANY-maze protocol items sub-heading. These values can then be used anywhere in a procedure - for example, to compare with the return value from a function (using a comparison operator), or to store in a user-defined variable.

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ANY-maze help topic T0491