# How do you access the elements of a vector in MATLAB?

## How do you access the elements of a vector in MATLAB?

Indexing with Element Positions For example, to access a single element of a matrix, specify the row number followed by the column number of the element. e is the element in the 3,2 position (third row, second column) of A . You can also reference multiple elements at a time by specifying their indices in a vector.

### How do you select part of an array in MATLAB?

To refer to multiple elements of an array, use the colon ‘:’ operator, which allows you to specify a range of elements using the form ‘start:end’. The colon alone, without start or end values, specifies all the elements in that dimension.

How do you randomly select an element from an array in MATLAB?

You must be using an older version of MATLAB, do this instead:

1. % create vector.
2. a = randn(100,1);
3. % determine how many elements is ten percent.
4. numelements = round(0.1*length(a));
5. % get the randomly-selected indices.
6. indices = randperm(length(a));
7. indices = indices(1:numelements);
8. % choose the subset of a you want.

How do you find the index of a vector element in MATLAB?

Description. k = find( X ) returns a vector containing the linear indices of each nonzero element in array X . If X is a vector, then find returns a vector with the same orientation as X . If X is a multidimensional array, then find returns a column vector of the linear indices of the result.

## How do you access the elements of an array?

Array elements are accessed by using an integer index. Array index starts with 0 and goes till size of array minus 1. Name of the array is also a pointer to the first element of array.

### How do you extract an element from a matrix in MATLAB?

MATLAB extracts the matrix elements corresponding to the nonzero values of the logical array. The output is always in the form of a column vector. For example, A(A > 12) extracts all the elements of A that are greater than 12. Or you could replace all the spaces in a string matrix str with underscores.

How do you call a specific element in a matrix in MATLAB?

For example, to access a single element of a matrix, specify the row number followed by the column number of the element. e is the element in the 3,2 position (third row, second column) of A . You can also reference multiple elements at a time by specifying their indices in a vector.

How do I select a random index in MATLAB?

1. % create vector.
2. a = randn(100,1);
3. % determine how many elements is ten percent.
4. numelements = round(0.1*length(a));
5. % get the randomly-selected indices.
6. indices = randperm(length(a));
7. indices = indices(1:numelements);
8. % choose the subset of a you want.

## How do you select a random sample in MATLAB?

To sample random integers with replacement from a range, use randi . To sample random integers without replacement, use randperm or datasample . To randomly sample from data, with or without replacement, use datasample .

### How do you find the index of an element in an array?

To find the position of an element in an array, you use the indexOf() method. This method returns the index of the first occurrence the element that you want to find, or -1 if the element is not found. The following illustrates the syntax of the indexOf() method.

What is use of ABS function in Matlab?

Description. example. Y = abs( X ) returns the absolute value of each element in array X . If X is complex, abs(X) returns the complex magnitude.

How do you store and access elements in an array?

Storing Data in Arrays. Assigning values to an element in an array is similar to assigning values to scalar variables. Simply reference an individual element of an array using the array name and the index inside parentheses, then use the assignment operator (=) followed by a value.