在特殊情况下创建更大的矩阵 [英] Create a larger matrix in special case

问题描述

我有两个向量:

A=[1 2 3 4]
B=[3 5 3 5]

我想从这些向量中找到一个矩阵，如下所示:

I want to find a matrix from these vectors like this:

您可以假设c是plot matrix，其中x轴是A，而y-axis是B:

you can suppose that c is a plot matrix, where the x-axis is A and y-axis is B:

c =
 0     4     0     4
 3     0     3     0
 0     0     0     0
 0     0     0     0

或:

 c1=
 0     1     0     1
 1     0     1     0
 0     0     0     0
 0     0     0     0

我的问题是因为我的向量很大，所以如何自动创建它.

My question is how to create it automatically because I have large vectors.

推荐答案

我假设A和B是坐标，并且您想以矩阵形式绘制"绘图，所以请尝试以下操作:

I'm assuming that A and B are coordinates, and you want to "draw" the plot in matrix form, so try this:

c = flipud(full(sparse(B, A, B)));

我添加了flipud来向上调整y轴的正方向.

I added flipud to adjust the positive direction of the y-axis upwards.

或者，您可以使用以下方法获得二进制矩阵:

Alternatively, you can obtain a binary matrix using this:

c1 = flipud(full(sparse(B, A, ones(size(A)))));

重要提示:要使此解决方案有效，A和B 必须包含正整数.试图绘制"具有非正或非整数位置的矩阵是没有意义的.

Important: for this solution to work, A and B must contain positive integer values. There is no sense in try to "plot" a matrix with non-positive or non-integer positions.

A = 1:4; B = [3, 4, 3, 4];   
c = flipud(full(sparse(B, A, B)))
c1 = flipud(full(sparse(B, A, ones(size(A)))))

结果是:

c =
     0     4     0     4
     3     0     3     0
     0     0     0     0
     0     0     0     0

c1 =
     0     1     0     1
     1     0     1     0
     0     0     0     0
     0     0     0     0

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