add - Add two objects using `fimath` object

Syntax

c = F.add(a,b)

Description

c = F.add(a,b) adds objects a and b using fimath object F. This is helpful in cases when you want to override the fimath objects of a and b, or if the fimath properties associated with a and b are different. The output fi object c is always associated with the global fimath.

a and b must have the same dimensions unless one is a scalar. If either a or b is scalar, then c has the dimensions of the nonscalar object.

If either a or b is a fi object, and the other is a MATLAB built-in numeric type, then the built-in object is cast to the word length of the fi object, preserving best-precision fraction length.

Examples

In this example, c is the 32-bit sum of a and b with fraction length 16:

a = fi(pi);
b = fi(exp(1));
F = fimath('SumMode','SpecifyPrecision','SumWordLength',32,...
'SumFractionLength',16);
c = F.add(a,b) 

c =
 
    5.8599


          DataTypeMode: Fixed-point: binary point scaling
            Signedness: Signed
            WordLength: 32
        FractionLength: 16

Algorithm

c = F.add(a,b) is similar to

a.fimath = F;
b.fimath = F;
c = a + b
c =
    5.8599

          DataTypeMode: Fixed-point: binary point scaling
            Signedness: Signed
            WordLength: 32
        FractionLength: 16

             RoundMode: nearest
          OverflowMode: saturate
           ProductMode: FullPrecision
  MaxProductWordLength: 128
               SumMode: SpecifyPrecision
         SumWordLength: 32
     SumFractionLength: 16
         CastBeforeSum: true

but not identical. When you use add, the fimath properties of a and b are not modified, and the output fi object c is associated with the global fimath. When you use the syntax c = a + b, where a and b have their own fimath objects, the output fi object c gets assigned the same fimath object as inputs a and b. See fimath Rules for Fixed-Point Arithmetic in the Fixed-Point Toolbox User's Guide for more information.

add - Add two objects using fimath object

Syntax

Description

Examples

Algorithm

See Also

add - Add two objects using `fimath` object