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sgennd.f 2.2 kB

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  1. *> \brief \b SGENND
  2. *
  3. * =========== DOCUMENTATION ===========
  4. *
  5. * Online html documentation available at
  6. * http://www.netlib.org/lapack/explore-html/
  7. *
  8. * Definition:
  9. * ===========
  10. *
  11. * LOGICAL FUNCTION SGENND (M, N, A, LDA)
  12. *
  13. * .. Scalar Arguments ..
  14. * INTEGER M, N, LDA
  15. * ..
  16. * .. Array Arguments ..
  17. * REAL A( LDA, * )
  18. * ..
  19. *
  20. *
  21. *> \par Purpose:
  22. * =============
  23. *>
  24. *> \verbatim
  25. *>
  26. *> SGENND tests that its argument has a non-negative diagonal.
  27. *> \endverbatim
  28. *
  29. * Arguments:
  30. * ==========
  31. *
  32. *> \param[in] M
  33. *> \verbatim
  34. *> M is INTEGER
  35. *> The number of rows in A.
  36. *> \endverbatim
  37. *>
  38. *> \param[in] N
  39. *> \verbatim
  40. *> N is INTEGER
  41. *> The number of columns in A.
  42. *> \endverbatim
  43. *>
  44. *> \param[in] A
  45. *> \verbatim
  46. *> A is REAL array, dimension (LDA, N)
  47. *> The matrix.
  48. *> \endverbatim
  49. *>
  50. *> \param[in] LDA
  51. *> \verbatim
  52. *> LDA is INTEGER
  53. *> Leading dimension of A.
  54. *> \endverbatim
  55. *
  56. * Authors:
  57. * ========
  58. *
  59. *> \author Univ. of Tennessee
  60. *> \author Univ. of California Berkeley
  61. *> \author Univ. of Colorado Denver
  62. *> \author NAG Ltd.
  63. *
  64. *> \date December 2016
  65. *
  66. *> \ingroup single_lin
  67. *
  68. * =====================================================================
  69. LOGICAL FUNCTION SGENND (M, N, A, LDA)
  70. *
  71. * -- LAPACK test routine (version 3.7.0) --
  72. * -- LAPACK is a software package provided by Univ. of Tennessee, --
  73. * -- Univ. of California Berkeley, Univ. of Colorado Denver and NAG Ltd..--
  74. * December 2016
  75. *
  76. * .. Scalar Arguments ..
  77. INTEGER M, N, LDA
  78. * ..
  79. * .. Array Arguments ..
  80. REAL A( LDA, * )
  81. * ..
  82. *
  83. * =====================================================================
  84. *
  85. * .. Parameters ..
  86. REAL ZERO
  87. PARAMETER ( ZERO = 0.0E0 )
  88. * ..
  89. * .. Local Scalars ..
  90. INTEGER I, K
  91. * ..
  92. * .. Intrinsics ..
  93. INTRINSIC MIN
  94. * ..
  95. * .. Executable Statements ..
  96. K = MIN( M, N )
  97. DO I = 1, K
  98. IF( A( I, I ).LT.ZERO ) THEN
  99. SGENND = .FALSE.
  100. RETURN
  101. END IF
  102. END DO
  103. SGENND = .TRUE.
  104. RETURN
  105. END