How to replace specific values to all values of a bin ?

I have a code that reads my data, and distribute them into bins: [0,2),[2,4),[4 6].

T=readtable('data.txt')
X=T(:,1)
Y=discretize(X,[ 0 2 4 6])

I would like to set specific value into each bin depending on its value.

I would like to set value 1.6 for values in first bin, value 3.8 for values in in second bin and value 5.7 for values in last bin.

I mean I would like to replace all values in first bin with 1.6, replace all the values of second bin with 3.8 and replace all the values of the third bin with 5.7

Could you please help me?

Answer 1

[Steven Lord]

Specify the values input argument in your discretize call.

x = 6*rand(10, 1);
d = discretize(x, 0:2:6, [1.6, 3.8, 5.7]);
results = table(x, d)

results = 10×2 table
       x        d 
    _______    ___

    0.19796    1.6
     3.9069    3.8
     4.0021    5.7
    0.85789    1.6
     5.5115    5.7
     5.0587    5.7
     2.3297    3.8
      5.465    5.7
    0.73075    1.6
      5.858    5.7

Answer 2

[Image Analyst]

Did you try just a simple for loop with an If statement inside?

[Ivan Mich]

I tried :

n=length(X)
for i=1:n
if 0<=X<2
    X(i)=1.6
elseif 2<=X<4
    X(i)== 3.8
else 4<=X<=6
    X(i)==5.7
end
end

but no use...

[Image Analyst]

You can't do stuff like this 2<=X<4 in MATLAB. You need to break it up into two conditionals:

elseif (2 <= X) && (X < 4)

Fix the other lines of code as well, or just use Steve's solution.

[Steven Lord]

You can write 2 <= x < 4 in MATLAB. It's syntactically legal code. However it likely won't do what the poster wanted. It will return an array of true values the same size as x since 2 <= x is an array containing either true or false values (considered as 1 or 0 for relational operations respectively) and both 1 and 0 are less than 4.

If you were to type that in the Editor, Code Analyzer should underline that in orange, tell you that it probably doesn't do what you think it does, and offer the conditional split as a suggested fix.

[Walter Roberson]

There is one place that 2 <= x < 4 works: inside piecewise() statements

syms x
piecewise(2 <= x < 4, 1, 4 <= x <= 5, 2, symtrue, 0)

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