HOW TO CALL THE IMSL FORTRAN LIBRARIES FROM C by ...

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$Intel(R) Math Kernel Library for Linux* OS User's Guide$

* This example transposes a two dimensional matrix * and prints it out. */ double a[2] [3] = {11., 12., 13., 21., 22., 23.}; char title[] = ''2x3 matrix''; main () { extern void dtrnrr_(), dwrrrn_(); /* external subroutines */ long int nra=3, nca=2, lda=3; /* matrix a is nra by nca */ longintnrb=2,ncb=3,ldb=2; /*matrixbisnrbbyncb*/ long int itring=0, lstr=10; /* triangle option and title length */ double b[3][2]; /* transpose matrix a and save the result in matrix b */ dtrnrr_ (&nra, &nca, a, &lda, &nrb, &ncb, b, &ldb); /* write the matrix b with a title */ dwrrrn_ (title, &nrb, &ncb, b, &ldb, &itring, lstr); } The output from Solaris is: 2x3 matrix 1 2 3 1 11 12 13 2 21 22 23 2.2 Passing a Function as an Argument For the environments in this section, a C function can simply be passed to a Fortran subroutine as an argument. The following example shows how to pass a function to IMSL routine DQDNG. Note that myfunc references x as a pointer because Fortran will invoke myfunc and pass the address of x. /* * This example shows how to integrate a user supplied function, * myfunc, at the given interval [0,2]. */ #include #include 9
* * myfunc calculates and returns *x * exp(*x). x is a pointer * since Fortran calls myfunc and passes the address of x. */ double myfunc (x); double *x; { double exp (); return (*x * exp (*x)); } main () { extern void dqdng_(); double exp(), fabs(), myfunc(); double lower=0.e0, upper=2.e0, errabs=0.e0, errrel=1.e-7; double result, errest, exact; /* IMSL routine dqdng integrates a smooth function using a nonadaptive rule. */ dqdng_ (myfunc, &lower, &upper, &errabs, &errrel, &result, &errest); /* The exact answer is already known and it is 1 + exp(2). */ exact = l.e0 + exp(2.e0); /* print the result */ printf ("\nIntegral of y = x*exp(x) on [0,2].\n\n"); printf ("Exact answer = %8.5f\n", exact); printf ("IMSL dqdng_ = %8.5f\n", result); printf ("Error = %l2.5e\n", fabs (exact - result)); } The output from Solaris is: Integral of y = x*exp(x) on [0,2]. Exact answer = 8.38906 IMSL dqdng_ = 8.38906 Error = 0.00000e+00 2.3 Compilation and Linking 10
Page 1 and 2: HOW TO CALL THE IMSL FORTRAN LIBRAR
Page 3 and 4: How to Call the IMSL Fortran Librar
Page 5 and 6: 1. Syntax Differences Between C and
Page 7 and 8: double a[2] [3] = {11., 12., 13., 2
Page 9: 2. Unix Platforms The topics discus
Page 13 and 14: #include #define MAXN 100 main ()
Page 15 and 16: 3. Cray The Cray UNICOS environment
Page 17 and 18: main () { double exp(), fabs(), myf
Page 19 and 20: * print the result */ if (nerr) pri
Page 21 and 22: 2x3 matrix 1 2 3 1 11 12 13 2 21 22
Page 23 and 24: drnun (&nn, a); /* generate a pre-d
Page 25 and 26: 5.1 Passing a Character String Argu
Page 27 and 28: Exact answer = 8.38906 IMSL dqdng =
Page 29 and 30: if (nerr) printf ("IMSL: %2 differe
Page 31 and 32: The user should compile C and Fortr

HOW TO CALL THE IMSL FORTRAN LIBRARIES FROM C by ...

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