numpy仅在保留数组结构的同时对非零部件执行功能

Question

在numpy:

Foo = 
array([[ 3.5,  0. ,  2.5,  2. ,  0. ,  1. ,  0. ],
       [ 0. ,  3. ,  2.5,  2. ,  0. ,  0. ,  0.5],
       [ 3.5,  0. ,  0. ,  0. ,  1.5,  0. ,  0.5]])

我想在Foo上执行一个函数,只有非零元素被改变,即对于f(x)= x(非零)+5:

array([[ 8.5,  0. ,  7.5,  7. ,  0. ,  6. ,  0. ],
       [ 0. ,  8. ,  8.5,  7. ,  0. ,  0. ,  5.5],
       [ 8.5,  0. ,  0. ,  0. ,  6.5,  0. ,  5.5]])

另外我希望数组的形状/结构保持不变,所以我不认为Foo [np.nonzero(Foo)]会起作用......

我怎么做numpy？

谢谢!

Answer 1

In [138]: foo = np.array([[ 3.5,  0. ,  2.5,  2. ,  0. ,  1. ,  0. ],
                          [ 0. ,  3. ,  2.5,  2. ,  0. ,  0. ,  0.5],
                          [ 3.5,  0. ,  0. ,  0. ,  1.5,  0. ,  0.5]])
In [141]: mask = foo != 0

In [142]: foo[mask] = foo[mask]+5

In [143]: foo
Out[143]: 
array([[ 8.5,  0. ,  7.5,  7. ,  0. ,  6. ,  0. ],
       [ 0. ,  8. ,  7.5,  7. ,  0. ,  0. ,  5.5],
       [ 8.5,  0. ,  0. ,  0. ,  6.5,  0. ,  5.5]])