How to keep only 3 digits after the dot on a number?

Hello

I have an array (1000x11) of binary numbers like this :

   1   0   1   1   0   0   0   1   1   0   0
   0   0   0   1   0   1   1   0   1   0   0
   1   1   1   0   1   1   0   1   1   0   0
   0   0   0   1   1   0   1   1   0   1   1
   1   1   0   1   0   1   0   0   1   1   1
   0   1   0   0   1   0   0   0   0   0   1
   0   0   0   0   1   0   1   1   0   0   0
   1   0   1   0   0   0   1   1   0   1   0

And I want to turn each row into a float decimal (x) with the last 10 binary digits as the numbers after the dots. I did this:

   x = x(:, 1) + (x(:, 2:11) * 2.^(9:-1:0).') / 1000 

but I got :

x = 1.8260
x =0.1110
x =1.9900
x =1.1640
x =0.3050
x = 0.6640

and I get the error 'Index exceeds matrix dimensions' so I have to take only the first 3 digits after the dot. How do I do that?

[Stephen23]

"I get the error 'Index exceeds matrix dimensions' so I have to take only the first 3 digits after the dot"

How is the precision of a value in any way related to an indexing error?

[James Tursa]

What would help us is for you to give us a description of inputs and desired outputs, with some small examples. E.g.,

"I am starting with these binary digits 101101001 and I want to do calculations that turn it into the floating point number ___."

(you fill in this blank for us)

[Nick]

"I am starting with these binary digits 10110001100 and I want to do calculations that turn it into the floating point number 1.396 ."

Could you also please check the files I attached? Maybe the mistake is there

Answer 1

[Chunru]

Try the following:

x = randi([0 1], 4, 11) 
%x = x(:, 1) + (x(:, 2:11) * 2.^(9:-1:0).') / 1000 ;     % May not accurate
x = x * 2.^(0:-1:-10)'              % This is the binary value

[Nick]

I did but it says : Undefined operator '*' for input arguments of type 'cell'.

[Jan]

@EL C: There is no cell in Chunru's code. If you run another code, please post it.

@Chunru: "Not accurate" is not a matching expression: These are completely different interpretations of the binary string.

[Nick]

I just posted the whole code I am running. It is a genetic algorithm with binary coding.

[Jan]

Then a binary representation an in Chunru's answer is better than a pseudo decimal interpretation.

[Chunru]

When I said ""Not accurate", I meant the division by 1000 (rather 1024).