Documentation

mdlDerivatives

Compute the C MEX S-function's derivatives

Required

No

并出口ages

C, C++

Syntax

#define MDL_DERIVATIVESvoid mdlDerivatives(SimStruct *S)

Arguments

S

SimStruct representing an S-Function block.

Description

The Simulink®engine invokes this optional method at each time step to compute the derivatives of the S-function's continuous states. This method should store the derivatives in the S-function's state derivatives vector. In a C MEX S-function, usessGetdXto get a pointer to the derivatives vector.

Each time themdlDerivativesroutine is called, it must explicitly set the values of all derivatives. The derivative vector does not maintain the values from the last call to this routine. The memory allocated to the derivative vector changes during execution.

Note

If you haveSimulink Coder™, when generating code for a noninlined C MEX S-function that contains this method, make sure the method is not wrapped in a#if defined(MATLAB_MEX_FILE)statement. For example:

#define MDL_DERIVATIVES #if defined(MDL_DERIVATIVES) && defined(MATLAB_MEX_FILE) static void mdlDerivatives(SimStruct *S) { /* Add mdlDerivatives code here * } #endif
Thedefinestatement makes themdlDerivativesmethod available only to a MATLAB®MEX file. If the S-function is not inlined, theSimulink Coderproduct cannot use this method, resulting in link or run-time errors.

Example

For a C MEX S-function example, seecsfunc.c.

See Also

ssGetdx,Derivatives

Introduced before R2006a

Simulink Documentation
金宝app

Try MATLAB, Simulink, and Other Products

Get trial now