ExtractCurve()

The ExtractCurve() function copies a curve from a previously executed test defined by the test label, renames it, and plots the curve on the specified graph address. This  function allows comparisons between multiple previously run tests. By using the NoSimulation analysis option, tests can be created without actually launching a simulation, but instead to produce summary curves from previous tests.

By default, ExtractCurve extracts curves from single step simulations. You can extract curves from Multi-Step or Monte Carlo simulations by specifying the params keyword in the optional parameter string. The params keyword specifies a simulation step defined by the stepped parameter name and value. If multiple parameters are stepped, all parameter name-value pairs must be specified. This capability was introduced in version 8.10. The params keyword will be ignored in versions prior to 8.10.

A call to the ExtractCurve() function does the following:

  • Opens the graph containing the curve name from the report specified by the label argument.
  • Copies all attributes from that curve and plots it on the new graph address.
Note: For this function to operate, the name of the curve to extract must be unique on all graph sheets, or there will be multiple curves to extract, and this function will fail.

ExtractCurve() Syntax

The ExtractCurve() function has the following syntax with the arguments explained in the table below:
ExtractCurve(label, curve_name_to_extract, new_curve_name, graph_name, grid_index, axis_name, OPTIONAL_PARAMETER_STRING)
Arg # Argument Name Description
1 label Report label on the previously run test
2 curve_name_to_extract Name of the curve to extract
3 new_curve_name New name for the curve
Note: For your curve to appear in the report, you must prefix the curve name with "DVM".
4 graph_name Name of the graph for the new test report*
5 grid_index Grid on which to place the curve*
6 axis_name Axis on a particular grid*
7 OPTIONAL_PARAMETER_STRING A space-separated set of KEY=VALUE pairs that define additional parameters**

* For additional information about graph_name, grid_index, and axis_name, see Graph Address System.

** For additional information about OPTIONAL_PARAMETER_STRING, see Optional Parameters.

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Example

The following call to the ExtractCurve() function copies a Bode diode, forward-biased curve taken from a SIMetrix simulation and adds it to a graph with the SIMPLIS simulation data for comparison.

ExtractCurve(TEMP=-40|Body Diode|SIMetrix, DVM SIMetrix, DVM SIMetrix, Body Diode Forward Biased, A1, vertical, xlabel=Body Diode Forward Voltage ylabel=Body Diode Forward Current color=green ygrid=5)

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Optional Parameters

The following syntax rules apply to the OPTIONAL_PARAMETER_STRING  argument:

  • The OPTIONAL_PARAMETER_STRING  value must not contain a comma.
  • The OPTIONAL_PARAMETER_STRING  is parsed on the equal sign.
  • Since the argument is parsed on the equal sign, the value itself must not contain an equal sign. For example, the following is an invalid entry: 
    ylabel=Body Diode Forward Current Temp=-40
    In this case , the program would read this incorrectly as two optional parameters:
    • ylabel=Body Diode Forward Current
    • Temp=-40

Spaces in values are allowed as long as no spaces are on either side of the equal sign. Thee three examples below illustrate this:

  • ylabel=Body Diode Forward Current: valid entry with no spaces around the equal sign
  • ylabel =Body Diode Forward Current: invalid entry with space before equal sign
  • ylabel= Body Diode Forward Current: invalid entry with space after equal sign

The following table lists the available formatting options for use in the OPTIONAL_PARAMETER_STRING argument.

Parameter Syntax Value Type Description
xgrid=positive_integer Any positive integer Specifies space between the x gridlines
  • params=param_name1:param_value1
  • params=param_name1:param_value1~param_name2:param_value2
 Parameter name and value pair, delimited by a colon. Multiple parameter name=pairs are joined with a tilde (~). Used for a Monte Carlo or Multi-Step simulation to extract a curve from a specific simulation step defined by the stepped parameter name and value pair(s).
ygrid=positive_integer Any positive integer Specifies space between the y gridlines
xscale=lin | log One of two options:
  • lin: plot x-axis in linear units
  • log: plot x-axis in logarithmic units
 Specifies the units for the x axis
yscale=lin | log O ne of two options:
  • lin: plot y-axis in linear units
  • log: plot y-axis in logarithmic units
 		 Specifies the units for the y axis
xlabel=string Any alphanumeric string Specifies a label for the x axis
ylabel=string Any alphanumeric string Specifies a label for the y axis

The ArbitraryBodePlot()function ignores this option if curves are placed on multiple grids.
xunits=string Any alphanumeric string Specifies the units label for the x axis
yunits=string Any alphanumeric string Specifies the units label for the y axis.

The  ArbitraryBodePlot()  function ignores this option.

xMinlimit=integer Any positive or negative integer Specifics the minimum x-axis limit
xMaxlimit=integer Any positive or negative integer Specifics the maximum x-axis limit
yMinlimit=integer Any positive or negative integer Specifics the minimum y-axis limit
yMaxlimit=integer Any positive or negative integer Specifics the maximum y-axis limit
showpoints=TRUE | FALSE TRUE or FALSE Specifies whether or not to show points on graph.
color=color_specification One of three options to specify the color:
  • Color-name alias
  • Hexadecimal color
  • SIMETRIX sequence
 Specifies the color for the curve.

Note: See the next section for information on these three methods for specifying a color..

Specifying a Color

You have three options for specifying the color for a curve:

  • Color-name Alias
  • Hexadecimal Color
  • SIMetrix Sequence

Color-name Alias

The syntax for the color-name alias is as follows: 
color=color_name
where color_name is one of the 16 built-in color aliases as listed in the following table with the hexadecimal code.
Color Name Alias Hex Code
 
 Red #FF0000
 
 Green #008000
 
 Blue #0000FF
 
 Teal #008080
 
 Purple #800080
 
 Maroon #800000
 
 Navy #000080
 
 Black #000000
 
 Magenta #FF00FF
 
 Lime #00FF00
 
 Salmon #FA8072
 
 Medium violet red #C71585
 
 Brown #A52A2A
 
 Indigo #4B0082
 
 Medium orchid #BA55D3
 
 Blue violet #8A2BE2

Hexadecimal color

The syntax for the hexidecimal color is as follows: 
color=#rrggbb
where rr, gg, and bb are hex numbers from 00 to FF.

You can specify any color for the curve by using a hexadecimal specification.

SIMetrix Sequence

The syntax for the SIMetrix sequence method of specifying a color is as follows: 
color=SEQ:n
where n is a positive integer between 1 and 20.

SIMetrix has eight default curve colors, starting with red, green, blue, etc.

To change and extend these colors to a maximum of 20 user-defined curve colors, follow these steps:

  1. From the menu bar, select File ▶ Options ▶ Colour....
  2. Double click a curve item in the list and then select another color from the palette, and click OK.
Note: If you do not set each Curve item in the list, the sequence wraps; for example, with the default curve colors, SEQ:9 yields the same curve color as SEQ:1.

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Using ExtractCurve() in a Script

The ExtractCurve() function is also available as a SIMetrix script function and can be called from a post-process or a final-process script. Calling this function from a script is useful when you need to generate a large number of curves and/or if the length of the arguments makes the testplan difficult to read or edit.

The syntax for the function in a script is as follows: 
SimplisDVMAdvancedUtilMeasurementExtractCurve(array, log_file)
Argument Description
array A string array that contains the normal arguments to the ExtractCurve() function
log_file The DVM log file that is an argument passed into the post and final process scripts

The Example above could be generated in a post-process script with the statement below:

Note: The array argument is bounded by open and close brackets [ ], and the string elements in the array are each enclosed in single quotes. 
Let return = SimplisDVMAdvancedUtilMeasurementExtractCurve([ 'TEMP=-40|Body Diode|SIMetrix', 'DVM SIMetrix', 'DVM SIMetrix', 
+           'Body Diode Forward Biased', 'A1', 'vertical', 'xlabel=Body Diode Forward Voltage ylabel=Body Diode Forward Current color=green ygrid=5' ], log_file)
  • The return value from this function is a real value with 0 indicating success and 1 indicating an error.
  • Error messages are displayed in the command shell for each function call.
Note: Using the script function in a post or final process script produces slightly different results than calling this function from a testplan. The post-process script does not set the vectors_to_keep argument because this would need to be performed before the simulation run executes. The simplest way to keep the necessary vectors during a simulation run is to place a voltage probe on the required schematic node and uncheck each Analysis checkbox in the edit dialog. This probe would then keep the voltage or current to which it is attached but would not create a curve.

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