C Copyright(C) 1999-2020 National Technology & Engineering Solutions C of Sandia, LLC (NTESS). Under the terms of Contract DE-NA0003525 with C NTESS, the U.S. Government retains certain rights in this software. C C See packages/seacas/LICENSE for details SUBROUTINE QAAVAL (MXND, NODES, ANGLES, QRAT, AREA, XN, YN, CAREA) C*********************************************************************** C SUBROUTINE QAAVAL = CALCULATES THE INTERIOR ANGLES OF A QUAD AND C THE RATIO OF LARGEST TO SMALLEST ANGLE C*********************************************************************** C VARIABLES USED: C NODES = THE FOUR NODES OF THE ELEMENT IN CCW ORDER C ANGLES = THE FOUR INTERIOR ANGLES IN THE ORDER 4-1, 1-2, 2-3, 3-4 C QRAT = THE RATIO OF THE LARGEST TO THE SMALLEST ANGLE C CAREA = .TRUE. IF THE AREA IS TO BE CALCULATED C AREA = ELEMENT'S AREA C*********************************************************************** DIMENSION NODES (4), ANGLES (4), AG (4), XN (MXND), YN (MXND) LOGICAL CAREA PI = ATAN2(0.0, -1.0) TWOPI = PI + PI IF (CAREA) THEN N1 = NODES (1) N2 = NODES (2) N3 = NODES (3) N4 = NODES (4) AREA = 0.5 * ( (XN (N3) - XN (N1)) * (YN (N4) - YN (N2)) & - (YN (N3) - YN (N1)) * (XN (N4) - XN (N2))) ENDIF DO 100 I = 1, 4 IF (I .EQ. 4) THEN J = 1 ELSE J = I + 1 ENDIF N1 = NODES (I) N2 = NODES (J) IF ( (XN (N2) .EQ. XN (N1)) .AND. (YN (N2) .EQ. YN (N1))) THEN QRAT = 1.E + 10 RETURN ELSE AG (J) = ATAN2 (YN (N2) - YN (N1), XN (N2) - XN (N1)) ENDIF 100 CONTINUE DO 110 J = 1, 4 IF (J .EQ. 1) THEN I = 4 ELSE I = J - 1 ENDIF DIFF = AG (J) - AG (I) IF (DIFF .GT. PI) THEN DIFF = DIFF - TWOPI ELSEIF (DIFF .LT. - PI) THEN DIFF = DIFF + TWOPI ENDIF ANGLES (J) = PI - DIFF 110 CONTINUE QMIN = ANGLES (1) QMAX = ANGLES (1) DO 120 I = 2, 4 QMIN = AMIN1 (QMIN, ANGLES (I)) QMAX = AMAX1 (QMAX, ANGLES (I)) 120 CONTINUE IF (QMIN .GT. 0.) THEN QRAT = QMAX / QMIN ELSE QRAT = 1.0E10 ENDIF RETURN END