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indexing_variables [2015/05/06 11:53]
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-===== Indexing Variables ===== 
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-Using the following matrices we will discuss how to index any variable. For demonstration purposes we will use a matrix since every variable in Matlab operates like a matrix. 
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-x = [1 2 3; 4 5 6; 7 8 9] 
-y = [0 0 0; 1 1 1; 2 2 2] 
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-Indexing in Matlab doesn’t start with 0, rather 1. The method for indexing the very first element in matrix x is  
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-syntax ​   variable_name(row,​column) 
-x(1,1);  
-Matlabe will return the value 1 since it is the first element in matrix x.  
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-It is possible to index a specific range in any matrix. Using the : symbol. Colon by itself will select every element in that row or column. If the colon is used between two integers this indicates a range between the two integers. Look at the following examples for better understanding. 
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-z = x[:,​2] ​ 
-z will consists of all the rows in column 2. [2 ; 5 ; 8] 
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-z = x[1:2, 1:2] 
-z will be a 2x2 matrix composed of [1 2 ; 4 5] 
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-For more information on the colon type “help :” in the command window. 
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indexing_variables.1430934793.txt.gz · Last modified: 2015/05/06 11:53 by petersen