set rounding mode in stateflow

i try to calculate in stateflow with action language C

input_a => fixdt(1,16,1e-3,0)

input_b => fixdt(1,32,1e-7,0)

output_c = > fixdt(1,16,1e-3,0)

output_c = input_a + input_b

In this case, the rounding mode of ouput_c is always floor in stateflow chart.

But, i want to make the ouput with round or nearest in chart.

Is there any option to set rounding mode as round or nearest with action language C in stateflow chart?

[Manikanta Aditya]

You might consider handling the rounding in your calculations explicitly. For example, you could add 0.5 to the sum before truncating (which is equivalent to flooring), effectively implementing rounding to the nearest integer.

output_c = floor(input_a + input_b + 0.5);

[진회]

thank you for comment.

that is usefull technique!

[Manikanta Aditya]

Cool.

Answer 1

[Angelo Yeo]

(1) "In this case, the rounding mode of ouput_c is always floor in stateflow chart."

>> Not true. It depends on conversion mode: offline or online conversion.

Offline conversions initialize data during code generation. Offline conversions are designed to maximize accuracy. These conversions round the resulting quantized integer to its nearest integer value.

Online conversions perform casting operations during run time. Online conversions are designed to maximize computational efficiency. Instead of rounding Q to its nearest integer, online conversions round to the floor (except for division, which can round to 0, depending on the C compiler).

(2) "Is there any option to set rounding mode as round or nearest with action language C in stateflow chart?"

>> No, as long as you use Charts for run time.

(3) My answers are quoted rom the doc below. See the doc for more information.

Fixed-Point Data in Stateflow Charts - MATLAB & Simulink (mathworks.com)

(4) If you think this design does not meet your requirement, please reach out to technical support team in order to submit an enhancement request.

Contact Support - MATLAB & Simulink (mathworks.com)

[진회]

thank you for your comment!

i will try your recomendation by following you contents.