• 1 parentheses
• 2 square_brackets
  • 2.1 square brackets
  • 2.2 using square brackets and boolean operators

parenthesis ( and ) are used to contain the parameters in a function for example vector(0,0,1)

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 ;

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=¹⁾*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 ;