In this case, the right side must contain the same number of elements as A. 2) Distinguish between matrix and vector array variables in MATLAB. On the left side of an assignment statement, A(:) fills A, preserving its shape from before. Define, index, and manipulate vectors and matrices in MATLAB. Is all the elements of A, regarded as a single column. No mystery here: a vector in MATLAB (as elsewhere) is a one-dimensional array of elements of the same data type. Is the k th page of three-dimensional array A. The following table describes its use for this purpose (let us have a matrix A) − Format You can use the colon operator to create a vector of indices to select rows, columns or elements of arrays. Here we discuss the Introduction to MATLAB Indexing and its different Examples as well as its input and output.MATLAB executes the statement and returns the following result −Ġ 0.3927 0.7854 1.1781 1.5708 1.9635 2.3562 As an additional feature, indexing can also be used to compare values of arrays. We can use indexing to obtain the value present at any desired location in an array. In this article, we have learnt how the indexing works in MATLAB. For the values in ‘X’, which are greater than ‘Y’, the output array has a ‘0’. 0 showing value in X is not less than Y at that particular cell and 1 showing that value at X is less than Y.Īs we can clearly see in the output above, we have obtained a ‘1’ for all values in ‘X’ which are less than corresponding values in ‘Y’. X = Y = We will pass the condition X < Y, to find out the elements in X, which are less than elements in Y.The output, in this case, will be an array of 0s and 1s. In the scenario where we want to know which all elements of an array X are greater than or less than another array Y, we can use this feature of indexing.Īll we need to do is pass the ‘’ sign between these 2 arrays as per our requirement. Let us understand how this can be achieved. It is also possible to index arrays based on logical operators. In the next scenario, let us assume that we need to get elements from the 1 st row till the 3 rd row, and from the 2 nd column till the 3 rd column.įor this purpose, we will specify the index range that we are looking for and will separate row and column ranges by a ‘colon’. All we did is passed the indices of required elements with the help of a vector to MATLAB. For our understanding, let us try to get the 3rd and 4th element of 3rd row.Īs we can clearly see in the output, we are able to get the 3 rd and 4 th elements of the 3 rd row, i.e, 11 and 2. We will use the same array as above for this example. Let us now take the scenario where we want to reference more than one element of a row. 7 is selected from the input array Example #2 X = Īs we can clearly see in the output, only the value present at position (2, 3), i.e. This is how our input and output will look like in MATLAB console: The Output that we obtain will be a single value present at the position (2, 3) in the array X. +number of dimensions for ii length(SA):-1:1 H zeros(SA(ii)S(ii),1) One index vector into A. The Syntax that we will use in MATLAB is: 1001 tips to speed up MATLAB programs Yair M. For this example, let us try to find out the cell at position (2, 3).

Vector indexing matlab