Alias()

DVM measurements results are output as scalars, which have a name and a value. The Alias() function allows you to create a duplicate scalar name with the same scalar value for any measurement. DVM automatically makes the measurements defined in the DVM Measurements dialog as well as any fixed probes which have probe measurements. For example, the following scalars are automatically generated for each Bode plot test objective:

gain_margin
phase_margin
gain_crossover_frequency

Comparing the gain_margin scalar value from one test with the gain_margin in another test with different operating conditions is difficult since both measurements have the same name. Using the Alias() function to rename the scalar to reflect unique operating conditions can help with this comparison.

Alias() Syntax

Single Step Alias Syntax

The single step Alias() function has the following syntax with the arguments described in the table below:

Alias(scalar_name, new_scalar_name)

Argument	Description
scalar_name	Default name for the scalar.
new_scalar_name	Name as you want it to appear in the report.

Note: The value of new_scalar_name is identical to the value of scalar_name. If the scalar you attempt to rename is not generated for this test, the Alias() testplan entry is ignored.

Important: Scalar names with spaces will produce errors when used with the Alias() function. The best solution is to create unique scalar names without spaces.

For more information on the Alias() function, see 6.6.1 Creating Scalar Aliases in the DVM tutorial.

Multi-Step Alias Syntax

When using the Multi-Step Analysis, parameters are stepped over a range of values during a single test. The single step alias syntax will no longer work for aliasing the scalar values, as all scalar names generated in all simulation steps will have the same aliased name.

To overcome this, a new aliasing scheme using a template system was added to DVM in revision 8.00f. If you would like to use this system, make sure your SIMetrix/SIMPLIS version is up to date. You can check your current version with the Help > About... menu, and check for updates with the Help > Check for Updates... menu.

The template syntax is extremely simple, using the stepped variable names enclosed in "%" signs to create unique scalar names. Here are two examples which describe the contemplating system:

Single Parameter Step

In this example, a single parameter representing the input voltage to the power supply, VIN, is stepped over 3 values, 360, 380, and 400 volts using an analysis testplan entry: Multi-Step( VIN , LIST , 360 , 380 , 400 ). When the scalar alias is created, the %VIN% in the new_scalar_name will be replaced with the stepped VIN value. For the following scalar alias:

Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V))

, three scalars will be created with names:

AVG(VLOAD_360_V)
AVG(VLOAD_380_V)
AVG(VLOAD_400_V)

You can then use these aliased scalar names with the CreateXYScalarPlot() function to create XY plots at the three input voltages.

Multiple Parameter Step

In this example, in addition the input voltage parameter, a parameter ILOAD is stepped over a range of values : 0.5, 1.0, 1.5, 2.0 using the testplan entry: Multi-Step( ILOAD , LIN , 4 , 0.5 ,2.0 ). Because there are two variable stepped, this is a nested or multiple parameter step. The total number of steps will be 3*4 or, 12 total simulation steps. A few example Alias functions and the created scalar aliases created are shown below.

Using the same Alias() function as in the single step example, the same three scalar aliases will be created:
```
Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V))
```
Creates these three scalars:
- AVG(VLOAD_360_V)
- AVG(VLOAD_380_V)
- AVG(VLOAD_400_V)
You can use the ILOAD stepped parameter value and four scalar aliases will be created, one for each ILOAD stepped value.
```
Alias(AVG(VLOAD), AVG(VLOAD_%ILOAD%_A))
```
Creates these four scalars:
- AVG(VLOAD_500m_A)
- AVG(VLOAD_1_A)
- AVG(VLOAD_1.5_A)
- AVG(VLOAD_2_A)
Note: The scalar aliases in this case will have the stepped parameter value converted to a string and represented in engineering notation. Thus, 0.5 A becomes 500mA, and 2.0 becomes 2.
Finally, you can use both stepped parameter names in the Alias function and each parameter name will be replaced with the stepped parameter value. A scalar alias will be created for each of the 12 simulation steps.
```
Alias(AVG(VLOAD), AVG(VLOAD_%VIN%_V_%ILOAD%_A))
```
Creates these 12 scalars:
- AVG(VLOAD_360_V_500m_A)
- AVG(VLOAD_360_V_1_A)
- AVG(VLOAD_360_V_1.5_A)
- AVG(VLOAD_360_V_2_A)
- AVG(VLOAD_380_V_500m_A)
- AVG(VLOAD_380_V_1_A)
- AVG(VLOAD_380_V_1.5_A)
- AVG(VLOAD_380_V_2_A)
- AVG(VLOAD_400_V_500m_A)
- AVG(VLOAD_400_V_1_A)
- AVG(VLOAD_400_V_1.5_A)
- AVG(VLOAD_400_V_2_A)

You can then use these aliased scalar names with the CreateXYScalarPlot() function to create XY plots at the three input voltages.