## Please I need help in MATLAB!!

Asked by Samira Zeinab

### Samira Zeinab (view profile)

on 25 Oct 2016
Latest activity Commented on by xiexiezaijian

### xiexiezaijian (view profile)

on 26 Oct 2016
I have to write a function that changes binary numbers to decimal numbers without using loops and without using the function bin2dec.

### Adam (view profile)

on 25 Oct 2016
If you have to write the function then write it. Then come and ask for help once you have made some effort.

### xiexiezaijian (view profile)

on 25 Oct 2016

since no loops and no bin2dec, this work could be done using the definition of binary number and vecterization operation. Take binary number 101 for example:
a = 101;
b = str2num(num2str(a)');
c = 2.^(2:-1:0)*b;%get the decimal number here
it is easy to handle the binary number with 4 or more digits and even numbers with points.
It seems that this is a question in MATLAB Cody.....

Samira Zeinab

### Samira Zeinab (view profile)

on 25 Oct 2016
I cannot use str2num . I have to use the point-wise operator :^ (dot ^ ) and the matrix multiplication operator applied to vectors. In particular, if u is a 1 by n vector and v is an n by 1 vector, then u v is the scalar given by u v = Σn i=1 u(i) v(i).)
xiexiezaijian

### xiexiezaijian (view profile)

on 26 Oct 2016
If no str2num......maybe you could do like this;
a = 101;
b = num2str(101) - '0';% since '1'-'0' = 1;
c = 2.^(2:-1:0)*b';
really like a Cody problem.... ### Walter Roberson (view profile)

Answer by Walter Roberson

### Walter Roberson (view profile)

on 25 Oct 2016

Hint: 2 to the 0, 2 to the 1, 2 to the 2, 2 to the 3... is 2 to the vector 0:3. Multiply each of those by the corresponding digit of the input and add the results