If-Else - MATLAB & Simulink (original) (raw)
Main Content
This example shows how to implement an if-else construct by using Simulink® blocks, Stateflow® Charts, and MATLAB® Function block.
C Construct
if (u1 > u2) { y1 = u1; } else { y1 = u2; }
Modeling Pattern for If-Else: Switch block
One method to create an if-else statement is to use a Switch block from the Simulink > Signal Routing library.
1. Open example model ex_if_else_SL.
The model contains the Switch block with the block parameter Criteria for passing first input of u2~=0. The software selects u1 if u2 is TRUE, otherwise u2 passes.
2. To build the model and generate code, press Ctrl+B.
The code implementing the if-else construct is in the ex_if_else_SL_step function in ex_if_else_SL.c:
/* External inputs (root inport signals with default storage) */ ExternalInputs U;
/* External outputs (root outports fed by signals with default storage) */ ExternalOutputs Y;
/* Model step function / void ex_if_else_SL_step(void) { / Switch: '/Switch' incorporates:
- Inport: '/u1'
- Inport: '/u2'
- RelationalOperator: '/Relational Operator' / if (U.u1 > U.u2) { / Outport: '/y1' / Y.y1 = U.u1; } else { / Outport: '/y1' */ Y.y1 = U.u2; }
/* End of Switch: '/Switch' */ }
Modeling Pattern for If-Else: Stateflow Chart
1. Open example model ex_if_else_SF.
The model contains an If-Else decision pattern that you add by right clicking inside the chart > Add Pattern in Chart > Decision > If-Else.
2. To build the model and generate code, press Ctrl+B.
The code implementing the if-else construct is in the ex_if_else_SF_step function in ex_if_else_SF.c:
/* External inputs (root inport signals with default storage) */ ExternalInputs U;
/* External outputs (root outports fed by signals with default storage) */ ExternalOutputs Y;
/* Model step function / void ex_if_else_SF_step(void) { / Chart: '/Chart' incorporates:
- Inport: '/u1'
- Inport: '/u2' / / If-Else / if (U.u1 >= U.u2) { / Outport: '/y1' / Y.y1 = U.u1; } else { / Outport: '/y1' */ Y.y1 = U.u2; }
/* End of Chart: '/Chart' */ }
Modeling Pattern for If-Else: MATLAB Function Block
1. Open example model ex_if_else_ML.
2. The MATLAB Function Block contains this function:
function y1 = fcn(u1, u2) if u1 > u2; y1 = u1; else y1 = u2; end
2. To build the model and generate code, press Ctrl+B.
The code implementing the if-else construct is in the ex_if_else_ML_step function in ex_if_else_ML.c:
/* External inputs (root inport signals with default storage) */ ExternalInputs U;
/* External outputs (root outports fed by signals with default storage) */ ExternalOutputs Y;
/* Model step function / void ex_if_else_ML_step(void) { / MATLAB Function: '/MATLAB Function' incorporates:
- Inport: '/u1'
- Inport: '/u2' / if (U.u1 >= U.u2) { / Outport: '/y1' / Y.y1 = U.u1; } else { / Outport: '/y1' */ Y.y1 = U.u2; }
/* End of MATLAB Function: '/MATLAB Function' */ }