Hello,

I have generated butterworth high pass filter(4 th order) coefficients using octave tool, I got the numerator & denominator coefficients of transfer function.But if want to use intrinsic function it is in the form of biquad.

Can some help me how to convert the following coefficients into sections as specified by **iir **function in dsp library?

**octave snippet:**

**[b,a] = butter(4,200/48000,"high");**

Regards

Sravan

Hi Sravan,

You can use "tf2sos" MATLAB (or equivalent) octave function to covert the [b a] coefficient array to an array of coefficients needed for cascaded biquad sections. Attached MATLAB script shows an example of how to do that. As you can see in the attached picture, Figure 1 shows the input plot, Figure 2 shows the output generated with the help of original [b a] coefficient array and Figure 3 shows the output generated with the help of cascaded biquad section coefficients. It works as expected.

Hope this helps.

Thanks,

Mitesh