Why doesn't num2fixpt function return my expected counterpart fixed point value?

Hello,

I am trying to convert from float/double to fixed point notation, for instance let's use the number x = 0.39 as input.

I would like to convert x into its unsigned 16 bits flxed-point counterpart, to do so in C++ I am accustomed to use the expression , this will make that the fixed point version of 0.39 is 25559.

However, I cannot get that result if I make use of num2fixpt function, I am using it in the following way

num2fixpt(0.39, ufix(16))

ans =

     0

What am I doing wrong when using num2fixpt function?

Thanks in advance,

Regards

Answer 1

[Jyotsna Talluri]

num2fixpt function does not convert double/float to a fixed point notation, instead it converts value to a nearest value represented by fixed point data type.You can convert double value to fixed point data type using fi

 a = fi(0.39);
 T = numerictype(0, 16, 0);
 c = reinterpretcast(a, T) ;

Refer to the documentatin of numerictype and reinterpretcast

[Javier Cuadros]

Thanks for your reply Jyotsna.

But then, I see that using

a = fi(0.39);

produces

a = 

    0.3900

Which is my floating point number but not into a fixed point notation, is it?

Thanks again,