C======================================================================= C VDPMEX.F C C $Revision: 1.11 $ C C This is a FORTRAN representation of the Van der Pol system. C It works in conjunction with the the file simulink.f. C C To compile this system, use the syntax: C mex vdpmex.f simulink.f C C Note, the .F files are designed to be passed through the C language C preprocessor before passing them onto the fortran compiler. The C .f files are created from the .F files. C C C======================================================================= C Written: C Ned Gulley Apr 28, 1992 C Copyright 1990-2002 The MathWorks, Inc. C======================================================================= C C======================================================================= SUBROUTINE SIZES(SIZE) C .. Array arguments .. INTEGER*4 SIZE(*) C======================================================================= C Purpose: C Function to set size vector C Input arguments: C None C Output arguments: C SIZE a vector of model sizes C Description: C Sizes returns a vector which determines model characteristics. C This vector contains the sizes of the state vector and other C parameters. More precisely, C SIZE(1) number of continuous states C SIZE(2) number of discrete states C SIZE(3) number of outputs C SIZE(4) number of inputs C SIZE(5) number of discontinuous roots in the system C SIZE(6) set to 1 if the system has direct feedthrough of its C inputs, otherwise 0 C======================================================================= C .. Parameters .. INTEGER*4 NSIZES PARAMETER (NSIZES=6) C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. SIZE(1) = 2 SIZE(2) = 0 SIZE(3) = 1 SIZE(4) = 0 SIZE(5) = 0 SIZE(6) = 0 RETURN END SUBROUTINE INITCOND(X0) C .. Array arguments .. REAL*8 X0(*) C======================================================================= C Purpose: C Function to set initial condition vector C Input arguments: C None C Output arguments: C X0 a vector of initial conditions C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. X0(1) = 2.00 X0(2) = 0.00 RETURN END SUBROUTINE DERIVS(T, X, U, DX) C .. Scalar arguments .. REAL*8 T C .. Array arguments .. REAL*8 X(*), U(*), DX(*) C======================================================================= C Purpose: C Function to return derivatives C Input arguments: C T time C X state vector C U input vector C Output arguments: C DX state vector derivatives C Remark: C The state vector is partitioned into continuous and discrete C states. The first states contain the continuous states, and C the last states contain the discrete states. C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. DX(2) = X(2)*(1 - X(1)*X(1)) - X(1) DX(1) = X(2) RETURN END SUBROUTINE DSTATES(T, X, U, XNEW) C .. Scalar arguments .. REAL*8 T C .. Array arguments .. REAL*8 X(*), U(*), XNEW(*) C======================================================================= C Purpose: C Function to perform discrete state update C Input arguments: C T time C X state vector C U input vector C Output arguments: C XNEW next state values C Remark: C The state vector is partitioned into continuous and discrete C states. The first states contain the continuous states, and C the last states contain the discrete states. C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. RETURN END SUBROUTINE OUTPUT(T, X, U, Y) C .. Scalar arguments .. REAL*8 T C .. Array arguments .. REAL*8 X(*), U(*), Y(*) C======================================================================= C Purpose: C Function to return continuous outputs C Input arguments: C T time C X state vector C U input vector C Output arguments: C Y output vector C Remark: C The state vector is partitioned into continuous and discrete C states. The first states contain the continuous states, and C the last states contain the discrete states. C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. Y(1) = X(1) RETURN END SUBROUTINE DOUTPUT(T, X, U, Y) C .. Scalar arguments .. REAL*8 T C .. Array arguments .. REAL*8 X(*), U(*), Y(*) C======================================================================= C Purpose: C Function to return discrete outputs C Input arguments: C T time C X state vector C U input vector C Output arguments: C Y output vector C Remark: C The state vector is partitioned into continuous and discrete C states. The first states contain the continuous states, and C the last states contain the discrete states. C This procedure is called only if it is a sample hit. C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. RETURN END SUBROUTINE TSAMPL(T, X, U, TS, OFFSET) C .. Scalar arguments .. REAL*8 T,TS,OFFSET C .. Array arguments .. REAL*8 X(*), U(*) C======================================================================= C Purpose: C Function to return the sample and offset times C Input arguments: C T time C X state vector C U input vector C Output arguments: C TS sample time C OFFSET offset time C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. RETURN END SUBROUTINE SINGUL(T, X, U, SING) C .. Scalar arguments .. REAL*8 T C .. Array arguments .. REAL*8 X(*), U(*), SING(*) C======================================================================= C Purpose: C Function to return singularities C Input arguments: C T time C X state vector C U input vector C Output arguments: C SING singularities C======================================================================= C .. Local scalars .. C .. Local arrays .. C .. Executable statements .. RETURN END