### Scalar

Category

Interactor

Function

Generates successive scalar values over a specified range.

Syntax

Available only through the user interface.

Inputs

Name | Type | Default | Description
--- | --- | --- | ---
`data` | object | no default | object from which interactor attributes can be derived
`refresh` | flag | 0 | reset the interactor
`min` | scalar | minimum data value | minimum output value
`max` | scalar | maximum data value | maximum output value
`delta` | scalar | input dependent | increment between successive scalar outputs
`method` | string | input dependent | defines interpretation of delta input
`decimals` | integer | input dependent | number of decimal places to be displayed in output values
`start` | string | "midpoint" | describes how the default output should be calculated
`label` | string | "Scalar" | global name applied to interactor stand-ins

Outputs

Name | Type | Description
--- | --- | ---
`output` | scalar | interactor output

Functional Details

This interactor allows the user to interactively change a scalar value. The range of values over which the module acts is governed by its attributes (e.g., minimum, maximum, and delta), which in turn are either (1) specified by the parameter values in its `Set Attributes...` dialog box or (2) determined from input to the module (e.g., a data field). In the second case, the interactor is said to be "data driven."

If the interactor is not data-driven, its attributes are taken from its `Set Attributes...` dialog box (accessed from the `Edit` pull-down menu in the Control Panel).

Because the module is interactive, the user can change the current controlling value directly in Scalar's control panel.

Note: The module's control panel is invoked by double-clicking on its icon in the VPE window. Its configuration dialog box is accessed from the `Edit` pull-down menu in the same window.

`data` | is the object (usually a data field) from which the interactor can derive any or all of the minimum, maximum, and delta attributes when their corresponding input tab is up.
`refresh` | resets the interactor so that the output is computed from the current input. If `refresh` = 0 (the default), the output is recomputed only if the current output does not lie within the range of the current `data`. The default for the output of the interactor is defined by the start parameter.
`min` and `max` | specify the minimum and maximum values of the interactor's scalar output. If set, these values override those implied by `data`. If neither `min` nor `data` is specified, the interactor uses the minimum set in the `Set Attributes...` dialog box. If neither `max` nor `data` is specified, the interactor uses the maximum set in the `Set Attributes...` dialog box.
`delta` | specifies a scalar value as a factor for calculating the increment between successive outputs over the specified range. The actual value depends on the interpretation specified by `method` (see below).

`method`

specifies the interpretation of `delta`:

- "rounded": the increment (`max` - `min`) × `delta` is rounded to a "nice" number. The spacing between successive values will approximate the interval specified by `delta`. (For example, the default value of 0.01 specifies an interval of 1/100 of the specified range.)
- "relative": the interpretation is the same as for "rounded," but the increment is not rounded.
- "absolute": `delta` is the absolute value of the interval. (If `delta` has not been specified, its default is 1.)

  The default value for `method` depends on other input. The default is:

  - "rounded" if `data` is specified or if both `min` and `max` are specified.
  - "absolute" in all other cases.

`decimals` | specifies the number of decimal places displayed in the interactor. If neither `data` nor `delta` is specified, the interactor uses the value in its own `Set Attributes...` dialog box.
`start` | specifies how the default output should be calculated. Can be "minimum", "midpoint" or "maximum" (midpoint sets the value to the midpoint between min and max.)
`label` | is the global label of all instances of the corresponding interactor stand-in. An interactor instance's local label (set from the Control Panel) overrides a global label. By default, the global label is set by the user interface.

Example Visual Programs

Many example visual programs use the Scalar interactor. `DataDrivenInteractors.net` uses a data-driven scalar interactor.

See Also

Integer, IntegerList, ScalarList, Vector, VectorList

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