Practical 3: Arrays
Arrays
One-Dimensional Operations
MATLAB has a specific array or ‘element-by-element’ multiplication, •*, designed for one-dimensional arrays, that is also called ‘Hadamard product’ in mathematics, and uses a dot, •, before multiply sign, *, eg V1•*V2
Exercise: Multiplication with Arrays
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> First define A=linspace(0,5,11) and B=linspace(1,6,11), c=4, and d=-1 |
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> Find out what happens if you run the following equations: A*c+d A*c+d*B > What happens if you multiply? A*B Note: MATLAB sends you an error message that ‘Matrix dimensions should agree’. It means that you forgot to use a dot before the multiplication sign. Matrix multiplication MATLAB referred to will be taught in further courses. > Try it again with a dot to perform array multiplication: A.*B |
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> Type in the following commands to find out which one works. A*5 A.*5 5*A A/5 5/A 5./A A^2 2^A 2.^A
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