重塑Fortran90

时间:2016-12-16 18:34:13

标签: arrays fortran reshape

我需要将尺寸为3 * 8的二维矩阵(A)重塑为矩阵(B),其中维度为(6 * 4),如下例所示。

Matrix A 

1 2 1 2 1 2 1 2
5 6 5 6 5 6 5 6
7 8 7 8 7 8 7 8

Matrix B                       
    1 1 1 1
    2 2 2 2
    5 5 5 5
    6 6 6 6
    7 7 7 7
    8 8 8 8

我尝试使用循环进行以下操作,但对于大型矩阵来说似乎非常慢。我想是否可以在Fortran 90中使用RESHAPE函数进行重新整形。

        counter=1
        do i=1,size(A,2),2
            seq1(counter)=i
            counter=1+counter
        end do

        counter=1
        do i=2,size(A,2),2
          seq2(counter)=i
          counter=1+counter
        end do

        counter=1
        do i=1,size(A,1)*2,2
          S_1(counter)=i
          counter=1+counter
        end do

        counter=1
        do i=2,size(A,1)*2,2
          S_2(counter)=i
          counter=1+counter
        end do

        Do i=1,size(A,1)
          B(S_1(i),:)=A(i,seq1)
          B(S_2(i),:)=A(i,seq2)
        END DO

1 个答案:

答案 0 :(得分:0)

以下代码进行了相应的重新整形,但您应该通过分析器运行程序来衡量性能。您的优化标志有多积极?

  B(1:2,:) = reshape(source=A(1,:), shape=[2,4])
  B(3:4,:) = reshape(source=A(2,:), shape=[2,4])
  B(5:6,:) = reshape(source=A(3,:), shape=[2,4])

并扭转转型,

  A(1,:) = reshape(source=B(1:2,:), shape=[8])
  A(2,:) = reshape(source=B(3:4,:), shape=[8])
  A(3,:) = reshape(source=B(5:6,:), shape=[8])