Get the value of a computed expression. This command displays the value of the specified expression in either default units (none) or the units specified and provides a useful way  to experiment with computed expressions to determine if the syntax is correct.  Refer to Section 7 of “CyFlex Variables, Units, and Computed Expressions” for the rules of syntax. 


get_comp “expression”  u=[units] option=<output options>



Specify the expression to compute. Enclose in double quotes as shown in Examples.


Optional. Specify the units for the results of the computation and the display. The default is to use the default units.


Optional. Specify an output content preference:

  • verbose to display output with equal signs and units. This is the default.
  • simple to display output with units and without equal signs or carriage returns. This option is intended for automated scripts.
  • no-units to display output without equal signs, carriage returns, and units. This option is intended for automated scripts.


get_comp ” RPM * Torque”   u=hp

The above command displays the current power in units of horsepower.

get_comp ” ‘date=’ + @year_month_day() “

This example demonstrates string concatenation.  The single quote is used to enclose a literal string, the @year_month_day() function returns a string such ‘220217’ for Feb 17, 2022 and the + symbol is used to concatenate the 2 strings resulting in an output of 


get_comp  ” if( hr_meter_run ) then 100[psi] else 0[psi] ”  u=psi 

This example demonstrates a simple logical expression that will return either 100[psi] or 0[psi] depending on whether the logical variable ‘hr_meter_run’ is TRUE of FALSE.   If the “u=psi” argument is specified, the value would be returned in units of PA (pascals).

The following illustrates different outputs based on the specified output option.

get_comp “1[in_hg] + vap_pa” u=in_h2o option=verbose= 27.1407330011252199142291[in_h2o]

get_comp “1[in_hg] + vap_pa” u=in_h2o option=simple

get_comp “1[in_hg] + vap_pa” u=in_h2o option=no-units


You can wrap the [units] argument in ” ” or ‘ ‘ if you get an issue.

An example problem is:

    get_comp “200[gm/kw_hr]” u=lb/(hp_hr)


    bash: syntax error near unexpected token ‘(‘

To fix this, run it as follows:

    get_comp “200[gm/kw_hr]”  “u=lb/(hp_hr)”


See Also:

CyFlex Variables, Units and Computed Expressions, Creating User Computations and User Variables