在Mathematica中删除矩阵列的简单方法 [英] Simple way to delete a matrix column in Mathematica

问题描述

我正在尝试删除mathematica中的两个矩阵.做到这一点的一种优雅方法如下所示，即在新矩阵中将其指定为

I am trying to delete both a matrix in mathematica. An inelegant way of doing it is as I do below, i.e specifying it in a new matrix as

S = Table[
    Ss[[If[i < t, i, i + 1]]][[If[j < t, j, j + 1]]], {i, q}, {j, q}];  

目标是消除行和列t.

where the goal is to eliminate row and column t.

确实要删除一行很容易Delete [Ss，t].对于专栏，我想我可以做

Indeed delete a line is easy Delete[Ss,t]. For the column column I suppose I could do

Transpose[Delete[Transpose[Ss,t]]]  

我主要关心的是以尽可能最快的方式执行此操作.

My primary concern is to do it in a way that executes the fastest way possible.

更一般地说，是否有Mathematica运算符可以像不进行转置那样对行进行分割和切分一样容易?

More generally, is there a Mathematica operator that makes it as easy to slice and dice matrix columns as it is to do for rows without resorting to transpose?

推荐答案

我认为您正在寻找:

Drop[Ss,{t},{t}]  

时间:

ClearAll["Global`*"];

First@Timing[a = RandomInteger[1000, {5000, 5000}];]
0.34

First@Timing[Drop[a, {2}, {2}]]
0.11

而

First@Timing[Transpose@Delete[Transpose@Delete[a, 2], 2]]
0.5

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