sub

Subtract two fi objects using fimath object

Syntax

c = sub(F,a,b)

Description

c = sub(F,a,b) subtracts fi 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 of fi object c has no local fimath.

Examples

Subtract Two fi Objects Overriding Their fimath

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

c = 
    0.4233

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

c is the 32-bit difference of a and b, with fraction length 16.

Input Arguments

F — fimath

fimath object

fimath object to use for subtraction, specified as a fimath object.

a,b — Operands

scalars | vectors | matrices | multidimensional arrays

Operands, specified as scalars, vectors, matrices, or multidimensional arrays.

a and b must both be fi objects and 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.

Data Types: fi
Complex Number Support: Yes

Algorithms

C = sub(F,A,B)

or

C = F.sub(A,B)

is equivalent to

A.fimath = F;
B.fimath = F;
C = A - B;

except that the fimath properties of A and B are not modified when you use the functional form.

Extended Capabilities

C/C++ Code Generation

Generate C and C++ code using MATLAB® Coder™.

Usage notes and limitations:

• Code generation does not support the syntax F.sub(a,b). You must use the syntax sub(F,a,b).

HDL Code Generation
Generate Verilog and VHDL code for FPGA and ASIC designs using HDL Coder™.

Version History

Introduced before R2006a