double precision function dasum(n,dx,incx) c c takes the sum of the absolute values. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dtemp integer i,incx,m,mp1,n,nincx c dasum = 0.0d0 dtemp = 0.0d0 if(n.le.0)return if(incx.eq.1)go to 20 c c code for increment not equal to 1 c nincx = n*incx do 10 i = 1,nincx,incx dtemp = dtemp + dabs(dx(i)) 10 continue dasum = dtemp return c c code for increment equal to 1 c c c clean-up loop c 20 m = mod(n,6) if( m .eq. 0 ) go to 40 do 30 i = 1,m dtemp = dtemp + dabs(dx(i)) 30 continue if( n .lt. 6 ) go to 60 40 mp1 = m + 1 do 50 i = mp1,n,6 dtemp = dtemp + dabs(dx(i)) + dabs(dx(i + 1)) + dabs(dx(i + 2)) * + dabs(dx(i + 3)) + dabs(dx(i + 4)) + dabs(dx(i + 5)) 50 continue 60 dasum = dtemp return end SUBROUTINE DGEMV ( TRANS, M, N, ALPHA, A, LDA, X, INCX, $ BETA, Y, INCY ) * .. Scalar Arguments .. DOUBLE PRECISION ALPHA, BETA INTEGER INCX, INCY, LDA, M, N CHARACTER*1 TRANS * .. Array Arguments .. DOUBLE PRECISION A( LDA, * ), X( * ), Y( * ) * .. * * Purpose * ======= * * DGEMV performs one of the matrix-vector operations * * y := alpha*A*x + beta*y, or y := alpha*A'*x + beta*y, * * where alpha and beta are scalars, x and y are vectors and A is an * m by n matrix. * * Parameters * ========== * * TRANS - CHARACTER*1. * On entry, TRANS specifies the operation to be performed as * follows: * * TRANS = 'N' or 'n' y := alpha*A*x + beta*y. * * TRANS = 'T' or 't' y := alpha*A'*x + beta*y. * * TRANS = 'C' or 'c' y := alpha*A'*x + beta*y. * * Unchanged on exit. * * M - INTEGER. * On entry, M specifies the number of rows of the matrix A. * M must be at least zero. * Unchanged on exit. * * N - INTEGER. * On entry, N specifies the number of columns of the matrix A. * N must be at least zero. * Unchanged on exit. * * ALPHA - DOUBLE PRECISION. * On entry, ALPHA specifies the scalar alpha. * Unchanged on exit. * * A - DOUBLE PRECISION array of DIMENSION ( LDA, n ). * Before entry, the leading m by n part of the array A must * contain the matrix of coefficients. * Unchanged on exit. * * LDA - INTEGER. * On entry, LDA specifies the first dimension of A as declared * in the calling (sub) program. LDA must be at least * max( 1, m ). * Unchanged on exit. * * X - DOUBLE PRECISION array of DIMENSION at least * ( 1 + ( n - 1 )*abs( INCX ) ) when TRANS = 'N' or 'n' * and at least * ( 1 + ( m - 1 )*abs( INCX ) ) otherwise. * Before entry, the incremented array X must contain the * vector x. * Unchanged on exit. * * INCX - INTEGER. * On entry, INCX specifies the increment for the elements of * X. INCX must not be zero. * Unchanged on exit. * * BETA - DOUBLE PRECISION. * On entry, BETA specifies the scalar beta. When BETA is * supplied as zero then Y need not be set on input. * Unchanged on exit. * * Y - DOUBLE PRECISION array of DIMENSION at least * ( 1 + ( m - 1 )*abs( INCY ) ) when TRANS = 'N' or 'n' * and at least * ( 1 + ( n - 1 )*abs( INCY ) ) otherwise. * Before entry with BETA non-zero, the incremented array Y * must contain the vector y. On exit, Y is overwritten by the * updated vector y. * * INCY - INTEGER. * On entry, INCY specifies the increment for the elements of * Y. INCY must not be zero. * Unchanged on exit. * * * Level 2 Blas routine. * * -- Written on 22-October-1986. * Jack Dongarra, Argonne National Lab. * Jeremy Du Croz, Nag Central Office. * Sven Hammarling, Nag Central Office. * Richard Hanson, Sandia National Labs. * * * .. Parameters .. DOUBLE PRECISION ONE , ZERO PARAMETER ( ONE = 1.0D+0, ZERO = 0.0D+0 ) * .. Local Scalars .. DOUBLE PRECISION TEMP INTEGER I, INFO, IX, IY, J, JX, JY, KX, KY, LENX, LENY * .. External Functions .. LOGICAL LSAME EXTERNAL LSAME * .. External Subroutines .. EXTERNAL XERBLA * .. Intrinsic Functions .. INTRINSIC MAX * .. * .. Executable Statements .. * * Test the input parameters. * INFO = 0 IF ( .NOT.LSAME( TRANS, 'N' ).AND. $ .NOT.LSAME( TRANS, 'T' ).AND. $ .NOT.LSAME( TRANS, 'C' ) )THEN INFO = 1 ELSE IF( M.LT.0 )THEN INFO = 2 ELSE IF( N.LT.0 )THEN INFO = 3 ELSE IF( LDA.LT.MAX( 1, M ) )THEN INFO = 6 ELSE IF( INCX.EQ.0 )THEN INFO = 8 ELSE IF( INCY.EQ.0 )THEN INFO = 11 END IF IF( INFO.NE.0 )THEN CALL XERBLA( 'DGEMV ', INFO ) RETURN END IF * * Quick return if possible. * IF( ( M.EQ.0 ).OR.( N.EQ.0 ).OR. $ ( ( ALPHA.EQ.ZERO ).AND.( BETA.EQ.ONE ) ) ) $ RETURN * * Set LENX and LENY, the lengths of the vectors x and y, and set * up the start points in X and Y. * IF( LSAME( TRANS, 'N' ) )THEN LENX = N LENY = M ELSE LENX = M LENY = N END IF IF( INCX.GT.0 )THEN KX = 1 ELSE KX = 1 - ( LENX - 1 )*INCX END IF IF( INCY.GT.0 )THEN KY = 1 ELSE KY = 1 - ( LENY - 1 )*INCY END IF * * Start the operations. In this version the elements of A are * accessed sequentially with one pass through A. * * First form y := beta*y. * IF( BETA.NE.ONE )THEN IF( INCY.EQ.1 )THEN IF( BETA.EQ.ZERO )THEN DO 10, I = 1, LENY Y( I ) = ZERO 10 CONTINUE ELSE DO 20, I = 1, LENY Y( I ) = BETA*Y( I ) 20 CONTINUE END IF ELSE IY = KY IF( BETA.EQ.ZERO )THEN DO 30, I = 1, LENY Y( IY ) = ZERO IY = IY + INCY 30 CONTINUE ELSE DO 40, I = 1, LENY Y( IY ) = BETA*Y( IY ) IY = IY + INCY 40 CONTINUE END IF END IF END IF IF( ALPHA.EQ.ZERO ) $ RETURN IF( LSAME( TRANS, 'N' ) )THEN * * Form y := alpha*A*x + y. * JX = KX IF( INCY.EQ.1 )THEN DO 60, J = 1, N IF( X( JX ).NE.ZERO )THEN TEMP = ALPHA*X( JX ) DO 50, I = 1, M Y( I ) = Y( I ) + TEMP*A( I, J ) 50 CONTINUE END IF JX = JX + INCX 60 CONTINUE ELSE DO 80, J = 1, N IF( X( JX ).NE.ZERO )THEN TEMP = ALPHA*X( JX ) IY = KY DO 70, I = 1, M Y( IY ) = Y( IY ) + TEMP*A( I, J ) IY = IY + INCY 70 CONTINUE END IF JX = JX + INCX 80 CONTINUE END IF ELSE * * Form y := alpha*A'*x + y. * JY = KY IF( INCX.EQ.1 )THEN DO 100, J = 1, N TEMP = ZERO DO 90, I = 1, M TEMP = TEMP + A( I, J )*X( I ) 90 CONTINUE Y( JY ) = Y( JY ) + ALPHA*TEMP JY = JY + INCY 100 CONTINUE ELSE DO 120, J = 1, N TEMP = ZERO IX = KX DO 110, I = 1, M TEMP = TEMP + A( I, J )*X( IX ) IX = IX + INCX 110 CONTINUE Y( JY ) = Y( JY ) + ALPHA*TEMP JY = JY + INCY 120 CONTINUE END IF END IF * RETURN * * End of DGEMV . * END SUBROUTINE DGER ( M, N, ALPHA, X, INCX, Y, INCY, A, LDA ) * .. Scalar Arguments .. DOUBLE PRECISION ALPHA INTEGER INCX, INCY, LDA, M, N * .. Array Arguments .. DOUBLE PRECISION A( LDA, * ), X( * ), Y( * ) * .. * * Purpose * ======= * * DGER performs the rank 1 operation * * A := alpha*x*y' + A, * * where alpha is a scalar, x is an m element vector, y is an n element * vector and A is an m by n matrix. * * Parameters * ========== * * M - INTEGER. * On entry, M specifies the number of rows of the matrix A. * M must be at least zero. * Unchanged on exit. * * N - INTEGER. * On entry, N specifies the number of columns of the matrix A. * N must be at least zero. * Unchanged on exit. * * ALPHA - DOUBLE PRECISION. * On entry, ALPHA specifies the scalar alpha. * Unchanged on exit. * * X - DOUBLE PRECISION array of dimension at least * ( 1 + ( m - 1 )*abs( INCX ) ). * Before entry, the incremented array X must contain the m * element vector x. * Unchanged on exit. * * INCX - INTEGER. * On entry, INCX specifies the increment for the elements of * X. INCX must not be zero. * Unchanged on exit. * * Y - DOUBLE PRECISION array of dimension at least * ( 1 + ( n - 1 )*abs( INCY ) ). * Before entry, the incremented array Y must contain the n * element vector y. * Unchanged on exit. * * INCY - INTEGER. * On entry, INCY specifies the increment for the elements of * Y. INCY must not be zero. * Unchanged on exit. * * A - DOUBLE PRECISION array of DIMENSION ( LDA, n ). * Before entry, the leading m by n part of the array A must * contain the matrix of coefficients. On exit, A is * overwritten by the updated matrix. * * LDA - INTEGER. * On entry, LDA specifies the first dimension of A as declared * in the calling (sub) program. LDA must be at least * max( 1, m ). * Unchanged on exit. * * * Level 2 Blas routine. * * -- Written on 22-October-1986. * Jack Dongarra, Argonne National Lab. * Jeremy Du Croz, Nag Central Office. * Sven Hammarling, Nag Central Office. * Richard Hanson, Sandia National Labs. * * * .. Parameters .. DOUBLE PRECISION ZERO PARAMETER ( ZERO = 0.0D+0 ) * .. Local Scalars .. DOUBLE PRECISION TEMP INTEGER I, INFO, IX, J, JY, KX * .. External Subroutines .. EXTERNAL XERBLA * .. Intrinsic Functions .. INTRINSIC MAX * .. * .. Executable Statements .. * * Test the input parameters. * INFO = 0 IF ( M.LT.0 )THEN INFO = 1 ELSE IF( N.LT.0 )THEN INFO = 2 ELSE IF( INCX.EQ.0 )THEN INFO = 5 ELSE IF( INCY.EQ.0 )THEN INFO = 7 ELSE IF( LDA.LT.MAX( 1, M ) )THEN INFO = 9 END IF IF( INFO.NE.0 )THEN CALL XERBLA( 'DGER ', INFO ) RETURN END IF * * Quick return if possible. * IF( ( M.EQ.0 ).OR.( N.EQ.0 ).OR.( ALPHA.EQ.ZERO ) ) $ RETURN * * Start the operations. In this version the elements of A are * accessed sequentially with one pass through A. * IF( INCY.GT.0 )THEN JY = 1 ELSE JY = 1 - ( N - 1 )*INCY END IF IF( INCX.EQ.1 )THEN DO 20, J = 1, N IF( Y( JY ).NE.ZERO )THEN TEMP = ALPHA*Y( JY ) DO 10, I = 1, M A( I, J ) = A( I, J ) + X( I )*TEMP 10 CONTINUE END IF JY = JY + INCY 20 CONTINUE ELSE IF( INCX.GT.0 )THEN KX = 1 ELSE KX = 1 - ( M - 1 )*INCX END IF DO 40, J = 1, N IF( Y( JY ).NE.ZERO )THEN TEMP = ALPHA*Y( JY ) IX = KX DO 30, I = 1, M A( I, J ) = A( I, J ) + X( IX )*TEMP IX = IX + INCX 30 CONTINUE END IF JY = JY + INCY 40 CONTINUE END IF * RETURN * * End of DGER . * END subroutine daxpy(n,da,dx,incx,dy,incy) c c constant times a vector plus a vector. c uses unrolled loops for increments equal to one. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dy(1),da integer i,incx,incy,ix,iy,m,mp1,n c if(n.le.0)return if (da .eq. 0.0d0) return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments c not equal to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n dy(iy) = dy(iy) + da*dx(ix) ix = ix + incx iy = iy + incy 10 continue return c c code for both increments equal to 1 c c c clean-up loop c 20 m = mod(n,4) if( m .eq. 0 ) go to 40 do 30 i = 1,m dy(i) = dy(i) + da*dx(i) 30 continue if( n .lt. 4 ) return 40 mp1 = m + 1 do 50 i = mp1,n,4 dy(i) = dy(i) + da*dx(i) dy(i + 1) = dy(i + 1) + da*dx(i + 1) dy(i + 2) = dy(i + 2) + da*dx(i + 2) dy(i + 3) = dy(i + 3) + da*dx(i + 3) 50 continue return end subroutine dcopy(n,dx,incx,dy,incy) c c copies a vector, x, to a vector, y. c uses unrolled loops for increments equal to one. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dy(1) integer i,incx,incy,ix,iy,m,mp1,n c if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments c not equal to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n dy(iy) = dx(ix) ix = ix + incx iy = iy + incy 10 continue return c c code for both increments equal to 1 c c c clean-up loop c 20 m = mod(n,7) if( m .eq. 0 ) go to 40 do 30 i = 1,m dy(i) = dx(i) 30 continue if( n .lt. 7 ) return 40 mp1 = m + 1 do 50 i = mp1,n,7 dy(i) = dx(i) dy(i + 1) = dx(i + 1) dy(i + 2) = dx(i + 2) dy(i + 3) = dx(i + 3) dy(i + 4) = dx(i + 4) dy(i + 5) = dx(i + 5) dy(i + 6) = dx(i + 6) 50 continue return end double precision function ddot(n,dx,incx,dy,incy) c c forms the dot product of two vectors. c uses unrolled loops for increments equal to one. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dy(1),dtemp integer i,incx,incy,ix,iy,m,mp1,n c ddot = 0.0d0 dtemp = 0.0d0 if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments c not equal to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n dtemp = dtemp + dx(ix)*dy(iy) ix = ix + incx iy = iy + incy 10 continue ddot = dtemp return c c code for both increments equal to 1 c c c clean-up loop c 20 m = mod(n,5) if( m .eq. 0 ) go to 40 do 30 i = 1,m dtemp = dtemp + dx(i)*dy(i) 30 continue if( n .lt. 5 ) go to 60 40 mp1 = m + 1 do 50 i = mp1,n,5 dtemp = dtemp + dx(i)*dy(i) + dx(i + 1)*dy(i + 1) + * dx(i + 2)*dy(i + 2) + dx(i + 3)*dy(i + 3) + dx(i + 4)*dy(i + 4) 50 continue 60 ddot = dtemp return end double precision function dnrm2 ( n, dx, incx) integer next double precision dx(1), cutlo, cuthi, hitest, sum, xmax,zero,one data zero, one /0.0d0, 1.0d0/ c c euclidean norm of the n-vector stored in dx() with storage c increment incx . c if n .le. 0 return with result = 0. c if n .ge. 1 then incx must be .ge. 1 c c c.l.lawson, 1978 jan 08 c c four phase method using two built-in constants that are c hopefully applicable to all machines. c cutlo = maximum of dsqrt(u/eps) over all known machines. c cuthi = minimum of dsqrt(v) over all known machines. c where c eps = smallest no. such that eps + 1. .gt. 1. c u = smallest positive no. (underflow limit) c v = largest no. (overflow limit) c c brief outline of algorithm.. c c phase 1 scans zero components. c move to phase 2 when a component is nonzero and .le. cutlo c move to phase 3 when a component is .gt. cutlo c move to phase 4 when a component is .ge. cuthi/m c where m = n for x() real and m = 2*n for complex. c c values for cutlo and cuthi.. c from the environmental parameters listed in the imsl converter c document the limiting values are as follows.. c cutlo, s.p. u/eps = 2**(-102) for honeywell. close seconds are c univac and dec at 2**(-103) c thus cutlo = 2**(-51) = 4.44089e-16 c cuthi, s.p. v = 2**127 for univac, honeywell, and dec. c thus cuthi = 2**(63.5) = 1.30438e19 c cutlo, d.p. u/eps = 2**(-67) for honeywell and dec. c thus cutlo = 2**(-33.5) = 8.23181d-11 c cuthi, d.p. same as s.p. cuthi = 1.30438d19 c data cutlo, cuthi / 8.232d-11, 1.304d19 / c data cutlo, cuthi / 4.441e-16, 1.304e19 / data cutlo, cuthi / 8.232d-11, 1.304d19 / c if(n .gt. 0) go to 10 dnrm2 = zero go to 300 c 10 assign 30 to next sum = zero nn = n * incx c begin main loop i = 1 20 go to next,(30, 50, 70, 110) 30 if( dabs(dx(i)) .gt. cutlo) go to 85 assign 50 to next xmax = zero c c phase 1. sum is zero c 50 if( dx(i) .eq. zero) go to 200 if( dabs(dx(i)) .gt. cutlo) go to 85 c c prepare for phase 2. assign 70 to next go to 105 c c prepare for phase 4. c 100 i = j assign 110 to next sum = (sum / dx(i)) / dx(i) 105 xmax = dabs(dx(i)) go to 115 c c phase 2. sum is small. c scale to avoid destructive underflow. c 70 if( dabs(dx(i)) .gt. cutlo ) go to 75 c c common code for phases 2 and 4. c in phase 4 sum is large. scale to avoid overflow. c 110 if( dabs(dx(i)) .le. xmax ) go to 115 sum = one + sum * (xmax / dx(i))**2 xmax = dabs(dx(i)) go to 200 c 115 sum = sum + (dx(i)/xmax)**2 go to 200 c c c prepare for phase 3. c 75 sum = (sum * xmax) * xmax c c c for real or d.p. set hitest = cuthi/n c for complex set hitest = cuthi/(2*n) c 85 hitest = cuthi/float( n ) c c phase 3. sum is mid-range. no scaling. c do 95 j =i,nn,incx if(dabs(dx(j)) .ge. hitest) go to 100 95 sum = sum + dx(j)**2 dnrm2 = dsqrt( sum ) go to 300 c 200 continue i = i + incx if ( i .le. nn ) go to 20 c c end of main loop. c c compute square root and adjust for scaling. c dnrm2 = xmax * dsqrt(sum) 300 continue return end subroutine drot (n,dx,incx,dy,incy,c,s) c c applies a plane rotation. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dy(1),dtemp,c,s integer i,incx,incy,ix,iy,n c if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments not equal c to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n dtemp = c*dx(ix) + s*dy(iy) dy(iy) = c*dy(iy) - s*dx(ix) dx(ix) = dtemp ix = ix + incx iy = iy + incy 10 continue return c c code for both increments equal to 1 c 20 do 30 i = 1,n dtemp = c*dx(i) + s*dy(i) dy(i) = c*dy(i) - s*dx(i) dx(i) = dtemp 30 continue return end subroutine drotg(da,db,c,s) c c construct givens plane rotation. c jack dongarra, linpack, 3/11/78. c modified 9/27/86. c double precision da,db,c,s,roe,scale,r,z c roe = db if( dabs(da) .gt. dabs(db) ) roe = da scale = dabs(da) + dabs(db) if( scale .ne. 0.0d0 ) go to 10 c = 1.0d0 s = 0.0d0 r = 0.0d0 go to 20 10 r = scale*dsqrt((da/scale)**2 + (db/scale)**2) r = dsign(1.0d0,roe)*r c = da/r s = db/r 20 z = s if( dabs(c) .gt. 0.0d0 .and. dabs(c) .le. s ) z = 1.0d0/c da = r db = z return end subroutine dscal(n,da,dx,incx) c c scales a vector by a constant. c uses unrolled loops for increment equal to one. c jack dongarra, linpack, 3/11/78. c double precision da,dx(1) integer i,incx,m,mp1,n,nincx c if(n.le.0)return if(incx.eq.1)go to 20 c c code for increment not equal to 1 c nincx = n*incx do 10 i = 1,nincx,incx dx(i) = da*dx(i) 10 continue return c c code for increment equal to 1 c c c clean-up loop c 20 m = mod(n,5) if( m .eq. 0 ) go to 40 do 30 i = 1,m dx(i) = da*dx(i) 30 continue if( n .lt. 5 ) return 40 mp1 = m + 1 do 50 i = mp1,n,5 dx(i) = da*dx(i) dx(i + 1) = da*dx(i + 1) dx(i + 2) = da*dx(i + 2) dx(i + 3) = da*dx(i + 3) dx(i + 4) = da*dx(i + 4) 50 continue return end integer function idamax(n,dx,incx) c c finds the index of element having max. absolute value. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dmax integer i,incx,ix,n c idamax = 0 if( n .lt. 1 ) return idamax = 1 if(n.eq.1)return if(incx.eq.1)go to 20 c c code for increment not equal to 1 c ix = 1 dmax = dabs(dx(1)) ix = ix + incx do 10 i = 2,n if(dabs(dx(ix)).le.dmax) go to 5 idamax = i dmax = dabs(dx(ix)) 5 ix = ix + incx 10 continue return c c code for increment equal to 1 c 20 dmax = dabs(dx(1)) do 30 i = 2,n if(dabs(dx(i)).le.dmax) go to 30 idamax = i dmax = dabs(dx(i)) 30 continue return end SUBROUTINE XERBLA ( SRNAME, INFO ) * .. Scalar Arguments .. INTEGER INFO CHARACTER*6 SRNAME * .. * * Purpose * ======= * * XERBLA is an error handler for the Level 2 BLAS routines. * * It is called by the Level 2 BLAS routines if an input parameter is * invalid. * * Installers should consider modifying the STOP statement in order to * call system-specific exception-handling facilities. * * Parameters * ========== * * SRNAME - CHARACTER*6. * On entry, SRNAME specifies the name of the routine which * called XERBLA. * * INFO - INTEGER. * On entry, INFO specifies the position of the invalid * parameter in the parameter-list of the calling routine. * * * Auxiliary routine for Level 2 Blas. * * Written on 20-July-1986. * * .. Executable Statements .. * WRITE (*,99999) SRNAME, INFO * STOP * 99999 FORMAT ( ' ** On entry to ', A6, ' parameter number ', I2, $ ' had an illegal value' ) * * End of XERBLA. * END LOGICAL FUNCTION LSAME ( CA, CB ) * .. Scalar Arguments .. CHARACTER*1 CA, CB * .. * * Purpose * ======= * * LSAME tests if CA is the same letter as CB regardless of case. * CB is assumed to be an upper case letter. LSAME returns .TRUE. if * CA is either the same as CB or the equivalent lower case letter. * * N.B. This version of the routine is only correct for ASCII code. * Installers must modify the routine for other character-codes. * * For EBCDIC systems the constant IOFF must be changed to -64. * For CDC systems using 6-12 bit representations, the system- * specific code in comments must be activated. * * Parameters * ========== * * CA - CHARACTER*1 * CB - CHARACTER*1 * On entry, CA and CB specify characters to be compared. * Unchanged on exit. * * * Auxiliary routine for Level 2 Blas. * * -- Written on 20-July-1986 * Richard Hanson, Sandia National Labs. * Jeremy Du Croz, Nag Central Office. * * .. Parameters .. INTEGER IOFF PARAMETER ( IOFF=32 ) * .. Intrinsic Functions .. INTRINSIC ICHAR * .. Executable Statements .. * * Test if the characters are equal * LSAME = CA .EQ. CB * * Now test for equivalence * IF ( .NOT.LSAME ) THEN LSAME = ICHAR(CA) - IOFF .EQ. ICHAR(CB) END IF * RETURN * * The following comments contain code for CDC systems using 6-12 bit * representations. * * .. Parameters .. * INTEGER ICIRFX * PARAMETER ( ICIRFX=62 ) * .. Scalar Arguments .. * CHARACTER*1 CB * .. Array Arguments .. * CHARACTER*1 CA(*) * .. Local Scalars .. * INTEGER IVAL * .. Intrinsic Functions .. * INTRINSIC ICHAR, CHAR * .. Executable Statements .. * * See if the first character in string CA equals string CB. * * LSAME = CA(1) .EQ. CB .AND. CA(1) .NE. CHAR(ICIRFX) * * IF (LSAME) RETURN * * The characters are not identical. Now check them for equivalence. * Look for the 'escape' character, circumflex, followed by the * letter. * * IVAL = ICHAR(CA(2)) * IF (IVAL.GE.ICHAR('A') .AND. IVAL.LE.ICHAR('Z')) THEN * LSAME = CA(1) .EQ. CHAR(ICIRFX) .AND. CA(2) .EQ. CB * END IF * * RETURN * * End of LSAME. * END subroutine dswap (n,dx,incx,dy,incy) c c interchanges two vectors. c uses unrolled loops for increments equal one. c jack dongarra, linpack, 3/11/78. c double precision dx(1),dy(1),dtemp integer i,incx,incy,ix,iy,m,mp1,n c if(n.le.0)return if(incx.eq.1.and.incy.eq.1)go to 20 c c code for unequal increments or equal increments not equal c to 1 c ix = 1 iy = 1 if(incx.lt.0)ix = (-n+1)*incx + 1 if(incy.lt.0)iy = (-n+1)*incy + 1 do 10 i = 1,n dtemp = dx(ix) dx(ix) = dy(iy) dy(iy) = dtemp ix = ix + incx iy = iy + incy 10 continue return c c code for both increments equal to 1 c c c clean-up loop c 20 m = mod(n,3) if( m .eq. 0 ) go to 40 do 30 i = 1,m dtemp = dx(i) dx(i) = dy(i) dy(i) = dtemp 30 continue if( n .lt. 3 ) return 40 mp1 = m + 1 do 50 i = mp1,n,3 dtemp = dx(i) dx(i) = dy(i) dy(i) = dtemp dtemp = dx(i + 1) dx(i + 1) = dy(i + 1) dy(i + 1) = dtemp dtemp = dx(i + 2) dx(i + 2) = dy(i + 2) dy(i + 2) = dtemp 50 continue return end