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To find array elements that meet a condition, use find in conjunction with a relational expression. For example, find(X<5) returns the linear indices to the elements in X that are less than 5. To directly find the elements in X that satisfy the condition X<5, use X(X<5).
Find Array Elements That Meet Conditions. This example shows how to filter the elements of an array by applying conditions to the array. For instance, you can examine the even elements in a matrix, find the location of all 0s in a multidimensional array, or replace NaN values in data.
MATLAB has many functions that help create matrices with certain values or a particular structure. For example, the zeros and ones functions create matrices of all zeros or all ones. The first and second arguments of these functions are the number of rows and number of columns of the matrix, respectively.
16 sty 2013 · Perhaps you could try creating a 6x6 matrix full of zeros: M = zeros(6) Then just setting part of it to 1:9? M(4:6,4:6) = reshape(1:9, 3, 3)' (The ' symbol means transpose)
16 maj 2011 · If you have a vector of coordinate for a set of points, you might want to differentiate those points. To do that a concept called logical indexing will help you pull out a subset of those points easily.
MATLAB provides efficient functions to create some commonly used matrices. Create a 3 by 5 matrix with all elements equal to zero. The command zeros(m,n) creates an m by n array (matrix) of zeros.
5 wrz 2019 · points = unique([A(:, [1, 3]); A(:, [1, 4]); A(:, [2, 3]); A(:, [2, 4])], 'rows') is the simplest though posibly not the most efficient. edit: this may be marginally more efficient, though more obscure:
