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isreal

Determine whether filter uses real coefficients

Syntax

isreal(hd)
isreal(hs)

Description

isreal(hd) returns 1 (or true) if all filter coefficients for the filter hd are real, and returns 0 (or false) otherwise. Complex filters have one or more coefficients with nonzero imaginary parts.

isreal(hs) determines whether the filter coefficients of the filter System object™ hs are real, returning 1 if true and 0 if false.

    Note   Quantizing a filter cannot make a real filter into a complex filter.

Examples

Create a double-precision filter and a fixed-point filter. Then, test the coefficients of the fixed-point filter to see if they are strictly real.

d=fdesign.lowpass('n,fp,ap,ast',5,0.4,0.5,20);
hd=design(d,'ellip');
hd.arithmetic='fixed';
IsReal =isreal(hd);
% Returns a 1

Introduced in R2011a

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