Brackets

Brackets

Parentheses

Parenthesis ( and ) are used to contain the parameters in a function

For Example

Vector(0,0,1)

Square_Brackets

Square Brackets

Square Brackets [ and ] specify frame numbers and components

Square Brackets [ and ] are used at the end of a function call or parenthesis ( ) to specify the frames numbers and components

Example, add two signals and retrieve the component 1 from frame 5

Evaluate_Expression

/Expression= (TARGET::ORIGINAL::RFT1 + TARGET::ORIGINAL::RFT2)[5,1]

/Result_Name=RFT_ADD_X

/Result_Type=DERIVED

/Result_Folder=PROCESSED

;

for example, add two signals and retrieve the component 1 for all frames

Evaluate_Expression

/Expression= (TARGET::ORIGINAL::RFT1 + TARGET::ORIGINAL::RFT2)[-1,1]

/Result_Name=RFT_ADD_X

/Result_Type=DERIVED

/Result_Folder=PROCESSED

;

NOTE a frame of -1 means all frames

Extracting one "component" of data from signal

The following command will result in the DERIVED signal TEST containing the X component values of the TARGET RFT1.

Evaluate_Expression

/EXPRESSION=TARGET::ORIGINAL::RFT1::X

/RESULT_NAME=TEST

/RESULT_TYPE=DERIVED

! /RESULT_FOLDER=PROCESSED

;

Using Square Brackets and Boolean Operators

In this example, project a collection of markers onto the floor

whenever the z-component of a marker is less than a threshold (e.g. 0.08 in this example)

otherwise set the resulting frame to NO_DATA

Evaluate_Expression

/EXPRESSION=(((CURRENT_SIGNAL[-1,3])<0.08)/((CURRENT_SIGNAL[-1,3])<0.08))*VECTOR(1,1,0)*CURRENT_SIGNAL

/SIGNAL_TYPES=TARGET

/SIGNAL_FOLDER=ORIGINAL

/SIGNAL_NAMES=LFT1+LFT2+LFT3+RFT1+RFT2+RFT3

/RESULT_TYPES=TARGET

/RESULT_FOLDERS=GROUND

! /RESULT_NAME=

/APPLY_AS_SUFFIX_TO_SIGNAL_NAME=TRUE

;