这个纯函数的#1,#2咋理解,mathematica软件distances = SparseArray[{{1, 2} -> 5, {2, 1} -> 5, {1, 3} -> 2, {3, 1} -> 2, {3, 2} -> 2, {2, 3} -> 2, {2, 4} -> 4, {4, 2} -> 4, {3, 4} -> 5, {4, 3} -> 5, {4, 1} -> 6, {1, 4} -> 6, {4,
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![这个纯函数的#1,#2咋理解,mathematica软件distances = SparseArray[{{1, 2} -> 5, {2, 1} -> 5, {1, 3} -> 2, {3, 1} -> 2, {3, 2} -> 2, {2, 3} -> 2, {2, 4} -> 4, {4, 2} -> 4, {3, 4} -> 5, {4, 3} -> 5, {4, 1} -> 6, {1, 4} -> 6, {4,](/uploads/image/z/10139615-71-5.jpg?t=%E8%BF%99%E4%B8%AA%E7%BA%AF%E5%87%BD%E6%95%B0%E7%9A%84%231%2C%232%E5%92%8B%E7%90%86%E8%A7%A3%2Cmathematica%E8%BD%AF%E4%BB%B6distances+%3D+++SparseArray%5B%7B%7B1%2C+2%7D+-%3E+5%2C+%7B2%2C+1%7D+-%3E+5%2C+%7B1%2C+3%7D+-%3E+2%2C+%7B3%2C+1%7D+-%3E++++++2%2C+%7B3%2C+2%7D+-%3E+2%2C++++%7B2%2C+3%7D+-%3E+2%2C+%7B2%2C+4%7D+-%3E+4%2C+%7B4%2C+2%7D+-%3E+4%2C+%7B3%2C+4%7D+-%3E+5%2C+%7B4%2C+3%7D+-%3E++++++5%2C+%7B4%2C+1%7D+-%3E+6%2C+%7B1%2C+4%7D+-%3E+6%2C+%7B4%2C)
这个纯函数的#1,#2咋理解,mathematica软件distances = SparseArray[{{1, 2} -> 5, {2, 1} -> 5, {1, 3} -> 2, {3, 1} -> 2, {3, 2} -> 2, {2, 3} -> 2, {2, 4} -> 4, {4, 2} -> 4, {3, 4} -> 5, {4, 3} -> 5, {4, 1} -> 6, {1, 4} -> 6, {4,
这个纯函数的#1,#2咋理解,mathematica软件
distances =
SparseArray[{{1, 2} -> 5, {2, 1} -> 5, {1, 3} -> 2, {3, 1} ->
2, {3, 2} -> 2,
{2, 3} -> 2, {2, 4} -> 4, {4, 2} -> 4, {3, 4} -> 5, {4, 3} ->
5, {4, 1} -> 6, {1, 4} -> 6, {4, 5} -> 8, {5, 4} -> 8, {1, 5} ->
1, {5, 1} -> 1}, {5, 5}, Infinity];
{length, tour} =
FindShortestTour[Range[5],
DistanceFunction -> (distances[[#1, #2]] &)]
#1,#2咋理解,纯函数的操作对象是什么?
这个纯函数的#1,#2咋理解,mathematica软件distances = SparseArray[{{1, 2} -> 5, {2, 1} -> 5, {1, 3} -> 2, {3, 1} -> 2, {3, 2} -> 2, {2, 3} -> 2, {2, 4} -> 4, {4, 2} -> 4, {3, 4} -> 5, {4, 3} -> 5, {4, 1} -> 6, {1, 4} -> 6, {4,
f=distances[[#1, #2]] &]
令f函数作用于{x,y}
f/@{x,y},f@@{x,y}等
则#1就是x,#2就是y
相当于非纯函数f[x,y]
即distances[[x,y]]
当然x,y可以是两个点,如果是距离函数的话
在这里#1,#2表示的是位置,即所建立稀疏矩阵的指定的位置
比如distances[[3,4]]就表示,在矩阵中的3行4列的元素是多少,是5