MATLAB: Getting First Cycle in Simulink

simulink first cycle

I have a requirement, where I need to initialize some outputs during initialization to some specific values, and later their values might change as time elapses. So what I did is, I connected a Constant block (1) to a Unit Delay(1/z) passed it to a Not Gate and the output of which is given to a Triggered subsystem, where I'll initialize the outputs. Is this gonna work ? Or please suggest some other technique, if any ?

Best Answer

There are different ways to do the initialization. The Outport block has initial value. You can initialize through that. For complex initialization, you can put all those initialization in a subsystem, make it an Enabled subsystem or triggered subsystem. Then use some types of logic to switch between the initialization algorithm and your regular algorithm. At the output, use the Merge block to create the final output you want.

Related Solutions

MATLAB: How to initialize buses in Simulink

The ability to initialize buses is not available in Simulink. Only Simulink buses of the same datatype may be initialized using the following workaround.

To work around this issue, in the output port of the subsystem a vector of the correct number of bus elements may be specified for the "Initial Output" parameter: [1 1 1 1]. This vector can be used regardless of the hierarchical breakdown of the bus.

MATLAB: Simple for cycle!

Think what happens for massa_pos when i=1. Nothing happens, because massa(i) is negative. But when you get to i=7, you then get massa_pos(7)=massa(7). What is matlab to think massa_pos(1:6) consists of, when you have not told anything about it? A vector will be filled with 0s as default.

In your example, you can add a running counter;

negcounter=1;poscounter=1;
for i=1:length(massa)
       if massa(i) < 0
        massa_neg(negcounter) = massa(i); 
        negcounter=negcounter+1;
       else  
         massa_pos(poscounter) = massa(i);
         poscounter=poscounter+1;
       end
end

Alternatively, a more clean approach is to simply use logical indexing:

massa_neg=massa((massa < 0)); %all values of massa which is below 0
massa_pos=massa((massa >= 0)); %and, similarly, all values of massa which is greater than or equal to 0.

Best Answer

Related Solutions

MATLAB: How to initialize buses in Simulink

MATLAB: Simple for cycle!

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