PadRight
 Usage
• PadRight[list, n]通过在右边用零填充list构造一个长度为 n的列表。
• PadRight[list, n, x]通过重复元素 x 填充。
• PadRight[list, n, padding, m] 留下一个放在右边的m个元素的边距。
• PadRight[list,   ,  , ...  ]构成在层 i一个长度为  的嵌套列表。
Notes
• PadRight[list, n, ... ]总是返回一个长度为 n的列表。 • 参见 Mathematica 全书 : 节 1.8.6.
 Further Examples
Padding a list This makes a list of length  by padding to the right with x's.
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Using  gives padding on the left.
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Using an empty list you can see how a cyclic padding ends on the first element of the padding.
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Now the nonempty list is superimposed on the padding.
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Here the list is padded on the left by  elements.
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And here the first  elements of the list are dropped.
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This treats the list as cyclic.
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This has the same effect.
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Padding a matrix This pads a  x  matrix to give  rows and  columns.
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This does the same thing, but uses a  x  block to provide the padding.
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This shifts the matrix down  row and to the right  columns.
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Padding graphics Here is a nested list.
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This represents the list using Raster. (Raster starts from the lower-left corner so the picture seems upside-down.) Evaluate the cell to see the graphic.
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Here the list is padded.
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Evaluate the cell to see the graphic.
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Here are two different paddings.
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Evaluate the cell to see the graphic.
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Evaluate the cell to see the graphic.
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.
• 通过
，有效的规定循环重复 
， 然后在它们顶部强加列表，列表的最后一个元素放在 
的位置。
. 
. 
