PROGRAM HYPERBOLA77

      INTEGER I, J
      REAL X, Y, A, B, Y1, Y2
      REAL DX, DY
      INTEGER NX, NY

      PARAMETER (A = 5.0, B = 3.0)         ! 双曲線の係数
      PARAMETER (NX = 80, NY = 25)         ! 画面サイズ（文字単位）

      DX = 0.2                             ! X軸刻み
      DY = 0.3                             ! Y軸刻み

      DO 100 J = NY, 1, -1
         Y = (J - NY/2.0) * DY
         DO 110 I = 1, NX
            X = (I - NX/2.0) * DX
            IF (ABS(X) .LT. A) THEN
               WRITE(*, '(A)', ADVANCE='NO') ' '
            ELSE
               Y1 =  B * SQRT((X*X)/(A*A) - 1.0)
               Y2 = -Y1
               IF (ABS(Y - Y1).LT.DY/2.0.OR.ABS(Y - Y2).LT.DY/2.0) THEN
                  WRITE(*, '(A)', ADVANCE='NO') '*'
               ELSE
                  WRITE(*, '(A)', ADVANCE='NO') ' '
               ENDIF
            ENDIF
110      CONTINUE
         WRITE(*, *)
100   CONTINUE

      END



HYPERBOLA77.EXE【Intel Fortran Compiler】実行結果
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