 # Step-by-Step Guide to Resize a Matrix in MATLAB

Understanding how to manage the size of a matrix and arrays in MATLAB is essential for proper data exploration and data analysis in the field of science and engineering. This tutorial will provide you step-by-step instructions on how to resize a matrix in MATLAB.

## Step 1: Invoke the 'Size' Function

Before you can resize your matrix, it is necessary to first invoke the 'size' function. This is done by typing `(size(A))` in the command window, where `A` is the name of your matrix. This will output both the row-by-column dimensions of the matrix.

## Step 2: Change the Size

Once the current dimensions of the matrix have been determined, it is now possible to make changes to its size. This is done by typing `A=[1 2;3 4]` in the command window, where the first two numbers define the first row and the second two numbers define the second row. To make the matrix bigger, simply add more elements to the two numbers, whereas to make the matrix smaller, reduce the number of numbers.

## Step 3: Reshape the Array

It is also possible to change the number of rows and columns in the matrix by using the reshape function. To do this, type `reshape(A,[m,n])` in the command window, where `m` and `n` are the desired row and column dimensions of the new matrix. This is often used when manipulating images as it allows for a more intuitive way of changing the shape of the array.

## Step 4: Use the 'End' Command

It is also possible to specify the size of the matrix by giving an index to the end command. To do this, type `B=A(1:end,1:end)` in the command window, where the `:end` will create the row and column dimensions of the matrix.

## Step 5: Concatenate Arrays

It is also possible to concatenate arrays in MATLAB, which will allow you to combine two or more matrices into one matrix. To concatenate arrays, type `C=cat(1,A,B)` in the command window, where `A` and `B` are the names of the two matrices.

## Step 6: Use the 'Repmat' Function

The 'repmat' function can also be used to repeat the same matrix multiple times, which is useful when dealing with large matrices. To use this function, simply type `D=repmat(A,m,n)` in the command window, where `m` and `n` are the desired number of repetitions of the matrix.

## FAQ

### What is the 'Size' function?

The 'Size' function is used in MATLAB to determine the row-by-column dimensions of a matrix. This can be used to determine the size of a matrix before it is resized.

### How do I change the size of a matrix?

To change the size of a matrix, use the reshape function. This is done by typing `reshape(A,[m,n])` in the command window, where `m` and `n` are the desired row and column dimensions of the new matrix.

### How do I add more elements to the matrix?

To add more elements to the matrix, simply use the 'end' command. To do this, type `B=A(1:end,1:end)`, where the `:end` will create the row and column dimensions of the matrix.

### How do I concatenate arrays?

To concatenate two or more arrays, use the 'cat' function. This is done by typing `C=cat(1,A,B)` in the command window, where `A` and `B` are the names of the two matrices.

### How do I repeat the same matrix multiple times?

To repeat the same matrix multiple times, use the 'repmat' function. To do this, simply type `D=repmat(A,m,n)` in the command window, where `m` and `n` are the desired number of repetitions of the matrix.

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