what does "X = X./max(max(X))" means?>

>> X=[1,2,3,4]

X =

     1     2     3     4

>> X = X./max(max(X));
>> X

X =

    0.2500    0.5000    0.7500    1.0000

>> 

I understand from the output, but what does "./" means?

Answer 1

[Stephan]

Hi,

the dot means an elementwise operation. See here:

https://de.mathworks.com/help/matlab/ref/rdivide.html

For more information to this topic see:

https://de.mathworks.com/help/matlab/matlab_prog/array-vs-matrix-operations.html

Best regards

Stephan

[Matlaber]

What is the simple meaning of elementwise?

elementwise (not comparable) (mathematics) Obtained by operating on one element (of a matrix etc) at a time.

I cannot see the different between "./" and "/".

[Stephan]

try this:

A=magic(3)
b = [2,4,5]
result1 = A/b
result2 = A./b

or

A=magic(3)
b = [1 -2 3; -4 -5 -6; 7 8 -9]
A/b % mrdivide
A./b % rdivide

Read about the both operations:

https://de.mathworks.com/help/matlab/ref/mrdivide.html

https://de.mathworks.com/help/matlab/ref/rdivide.html

[Matlaber]

thanks!

"./" is element by element, one element by one element

Answer 2

[Matlaber]

https://slideplayer.com/slide/14985720/

source

Answer 3

[Abdulmanan Butt]

Hi,

It means,

You are dividing X matrix (element-wise) with the element of matrix X having maximum value.

Like in this case, max(X) or max(max(X)) will be 4, and you are going to divide matrix X with that 4, Where 4 will be divided to each element of matrix X in this element-wise division case, So you got the final result,

X= 0.2500    0.5000    0.7500    1.0000

Regards,

Abdulmanan Butt

[Matlaber]

Thanks.

If I didn't include ".", it give the same result too

>> X=[1,2,3,4]

X =

     1     2     3     4

>> X = X./max(max(X));
>> X

X =

    0.2500    0.5000    0.7500    1.0000
> X = X/max(max(X));
>> X

X =

    0.2500    0.5000    0.7500    1.0000

[Abdulmanan Butt]

Ok i got your point. Thats the only when we have one element in second matrix . Lets take an example,

X= [1 2 3 4]

Y=[1 2 3 4]

If we include "." we got answer [1 1 1 1]

and we dont include that dot, wwe will get answer 1.

Actually when we include ".", we will get bit to bit division, menas 1st element of one matrix will be divided by 1st element of second matrix

Kindly have a look on attachment.

Got the point ?

[Matlaber]

Thanks. I got it.

"." means element by element, usually one by one

Thanks for your reply.

[Abdulmanan Butt]

Yes..!!

Welcome.