Change values of a matrix if meet the condition

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Andres Serrano 2018-11-2

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编辑： James Tursa 2018-11-2

Hi guys a have a 2*2 matrix. and I want to substite the values of the 2 columns based in 2 different conditions. EX a= '1' '0' '0' '1'. For the first column if X=1 y=0.6 and if X=0 y=0.4. Similarly in column 2 if x=1 y=0.7 and if x=0 y=0.3. Therefore, new matrix b= '0.6' ' 0.4' '0.3' '0.7'.

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madhan ravi 2018-11-2

Please edit your question so that it’s easy to read

Andres Serrano 2018-11-2

condition.m

Hi Madhan, I have attached a script

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Answer 1

James Tursa 2018-11-2

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https://ww2.mathworks.cn/matlabcentral/answers/427666-change-values-of-a-matrix-if-meet-the-condition#answer_344870

编辑：James Tursa 2018-11-2

在 MATLAB Online 中打开

E.g., I think this is what you are asking for:

a = your matrix of 1's and 0's
p = your matrix of values (1st row corresponding to 0 values, 2nd row corresponding to 1 values)
c = 1:size(a,1):numel(a); % Set up for linear indexing
b = a; % An arbitrary matrix the same size as a
b(:) = p(bsxfun(@plus,a,c)); % Replace elements with appropriate p values (linear indexing)

On later versions of MATLAB you don't need bsxfun:

b(:) = p(a+c); % Replace elements with appropriate p values (linear indexing)

A sample run:

>> a = eye(2)
a =
     1     0
     0     1
>> p = [0.4 0.3; 0.6 0.7]
p =
    0.4000    0.3000
    0.6000    0.7000
>> c = 1:size(a,1):numel(a)
c =
     1     3
>> b = a
b =
     1     0
     0     1
>> b(:) = p(bsxfun(@plus,a,c))
b =
    0.6000    0.3000
    0.4000    0.7000