Mathematical Operators

Plus

NOTE: Pipeline command parameters use + as delimiter

If the user wants to use an expression containing a + in a command parameter that allows multiple signals, Visual3D will likely interpret this plus sign incorrectly.

The workaround is to use a mathematical function add() to express the addition.

add(a,b) -- adds two expressions.

Logical_Or

Logical Or

Logical_And

Logical And

Equals

= or == - Boolean Operator equals

Example: Comparing a model metric with a string

Consider a model metric that is defined as a string.

Set_Model_Metric

! /CALIBRATION_FILE=

/METRIC_NAME=TEST

/METRIC_VALUE="TTT"

;

Now compare it to the text string "TTT"

Evaluate_Expression

/EXPRESSION=MODEL::METRIC::TEST="TTT"

/RESULT_NAME=SCOTT

/RESULT_TYPE=METRIC

! /RESULT_FOLDER=PROCESSED

;

The text strings should be equal so the resulting signal contains a 1

Not_Equals

<> or >< - Boolean Operator "Not Equals"

Using the Adjective NOT

NOT can be used with the logical AND and logical OR

Example: Given a workspace containing 3 trials (*trial1.c3d, *trial2.c3d, and *trial3.c3d)

All trials are assigned a TAG labeled WALK

• trial1.c3d is also assigned a TAG labeled BAD

Select_Active_File

/FILE_NAME=WALK

/QUERY=BAD

;

This command results in *trial1.c3d being active

Select_Active_File

/FILE_NAME=WALK

/QUERY=NOT(BAD)

;

This command results in *trial2.c3d and *trial3.c3d being active.

Less_Than

< Boolean Operator less than

Example

Given two signals

TARGET::ORIGINAL::RFT1

TARGET::ORIGINAL::LFT1

Use the Boolean operator < to identify when the Z component of RFT1 is less than the Z component of LFT1

Evaluate_Expression

/EXPRESSION= TARGET::ORIGINAL::RFT1::Z < TARGET::ORIGINAL::LFT1::Z

/RESULT_NAME=RFT1_GREATER

/RESULT_TYPE=DERIVED

/RESULT_FOLDER=PROCESSED

;

The output signal will be 1 when RFT1::Z is less than LFT1::Z and 0 otherwise

Example - Foot Clearance

Given the following situation. Heel and Toe clearance are defined by two paths.

One might consider Foot clearance to be the lower value of the heel and toe clearance values at each frame.

Here is a simplified test of this

Make the Global Workspace Active.

Create 2 signals as follows

Evaluate_Expression

/EXPRESSION=LIST(1,2,3,4,5)

! /SIGNAL_TYPES=

! /SIGNAL_FOLDER=ORIGINAL

! /SIGNAL_NAMES=

! /SIGNAL_COMPONENTS=

/RESULT_TYPES=DERIVED

/RESULT_FOLDERS=PROCESSED

/RESULT_NAME=SIGNAL1

! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE

;

Evaluate_Expression

/EXPRESSION=LIST(5,4,3,2,1)

! /SIGNAL_TYPES=

! /SIGNAL_FOLDER=ORIGINAL

! /SIGNAL_NAMES=

! /SIGNAL_COMPONENTS=

/RESULT_TYPES=DERIVED

/RESULT_FOLDERS=PROCESSED

/RESULT_NAME=SIGNAL2

! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE

;

!create a new signal that is the lower value of the two signals

Evaluate_Expression

/EXPRESSION=(DERIVED::PROCESSED::SIGNAL1<=DERIVED::PROCESSED::SIGNAL2)*DERIVED::PROCESSED::SIGNAL1

+(DERIVED::PROCESSED::SIGNAL2<DERIVED::PROCESSED::SIGNAL1)*DERIVED::PROCESSED::SIGNAL2

! /SIGNAL_TYPES=

! /SIGNAL_FOLDER=ORIGINAL

! /SIGNAL_NAMES=

! /SIGNAL_COMPONENTS=

/RESULT_TYPES=DERIVED

/RESULT_FOLDERS=PROCESSED

/RESULT_NAME=SIGNAL_LOWER

! /APPLY_AS_SUFFIX_TO_SIGNAL_NAME=FALSE

;

Less_Than_Or_Equals

! style="text-align:left;" |      <= or =< Boolean Operator less than or equal to

Example:

Given two signals

TARGET::ORIGINAL::RFT1

TARGET::ORIGINAL::LFT1

Use the Boolean operator <= or the boolean operative =< to identify when the Z component of RFT1 is less than or equal to the Z component of LFT1

Evaluate_Expression

/EXPRESSION= TARGET::ORIGINAL::RFT1::Z <= TARGET::ORIGINAL::LFT1::Z

/RESULT_NAME=RFT1_GREATER

/RESULT_TYPE=DERIVED

/RESULT_FOLDER=PROCESSED

;

The output signal will be 1 when RFT1::Z is less than or equal toLFT1::Z and 0 otherwise

Greater_Than

> Boolean Operator greater than

Example:

Given two signals

TARGET::ORIGINAL::RFT1

TARGET::ORIGINAL::LFT1

Use the Boolean operator > to identify when the Y component of RFT1 is greater than the Y component of LFT1

Evaluate_Expression

/EXPRESSION= TARGET::ORIGINAL::RFT1::Y > TARGET::ORIGINAL::LFT1::Y

/RESULT_NAME=RFT1_GREATER

/RESULT_TYPE=DERIVED

/RESULT_FOLDER=PROCESSED

;

The output signal will be 1 when RFT1::Y is greater than LFT1::Y and 0 otherwise

Greater_Than_Or_Equals

>= Boolean Operator greater than or equals