fcfwrite
Write file containing filter coefficients
Syntax
fcfwrite(h)
fcfwrite(h,filename)
fcfwrite(...,'fmt')
Description
fcfwrite(h) writes a filter
coefficient ASCII file in a folder you choose, or your current MATLAB® working
folder. h can be a single filter object or a vector
of filter objects. On execution, fcfwrite opens
the Export Filter Coefficients to .FCF File dialog
box to let you assign a file name for the output file. You can choose
the destination folder within this dialog as well.
The default file name is untitled.fcf. When
you have DSP System Toolbox™ software, you can use fcfwrite(h) to
write filter coefficient files for multirate filters, adaptive filters,
and discrete-time filters.
fcfwrite(h,filename) writes
the filter coefficients and general information to a text
file called filename in your present MATLAB working
folder and opens the file in the MATLAB editor for you to review or
modify.
If you do not include a file extension in filename, fcfwrite adds
the extension fcf to filename.
fcfwrite(...,'fmt') writes
the filter coefficients in the format specified by the input argument fmt.
Valid fmt values are hex for
hexadecimal, dec for decimal, or bin for
binary representation of the filter coefficients.
Examples
To demonstrate fcfwrite, create a fixed-point
IIR filter at the command line, and then write the filter coefficients
to a file named iirfilter.fcf.
d=fdesign.lowpass; hd=design(d,'butter'); set(hd,'arithmetic','fixed'); fcfwrite(hd,'iirfilter.fcf');
Here is the output from fcfwrite as it
appears in the MATLAB editor. Not shown here is the filename — iirfilter.fcf as
specified and some comments at the top of the file.
%
%
% Coefficient Format: Decimal
%
% Discrete-Time IIR Filter (real)
% -------------------------------
% Filter Structure : Direct-Form II, Second-Order
% Sections
% Number of Sections : 13
% Stable : Yes
% Linear Phase : No
% Arithmetic : fixed
% Numerator : s16,13 -> [-4 4)
% Denominator : s16,14 -> [-2 2)
% Scale Values : s16,14 -> [-2 2)
% Input : s16,15 -> [-1 1)
% Section Input : s16,8 -> [-128 128)
% Section Output : s16,10 -> [-32 32)
% Output : s16,10 -> [-32 32)
% State : s16,15 -> [-1 1)
% Numerator Prod : s32,28 -> [-8 8)
% Denominator Prod : s32,29 -> [-4 4)
% Numerator Accum : s40,28 -> [-2048 2048)
% Denominator Accum : s40,29 -> [-1024 1024)
% Round Mode : convergent
% Overflow Mode : wrap
% Cast Before Sum : true
SOS matrix:
1 2 1 1 -0.22222900390625 0.88262939453125
1 2 1 1 -0.19903564453125 0.68621826171875
1 2 1 1 -0.18060302734375 0.5303955078125
1 2 1 1 -0.1658935546875 0.40570068359375
1 2 1 1 -0.154052734375 0.305419921875
1 2 1 1 -0.14453125 0.22479248046875
1 2 1 1 -0.136962890625 0.16015625
1 2 1 1 -0.13092041015625 0.10906982421875
1 2 1 1 -0.126220703125 0.06939697265625
1 2 1 1 -0.12274169921875 0.0399169921875
1 2 1 1 -0.12030029296875 0.01947021484375
1 2 1 1 -0.118896484375 0.0074462890625
1 1 0 1 -0.0592041015625 0
Scale Values:
0.41510009765625
0.371826171875
0.33746337890625
0.3099365234375
0.287841796875
0.27008056640625
0.25579833984375
0.2445068359375
0.23577880859375
0.22930908203125
0.22479248046875
0.22216796875
0.47039794921875
1 To write two or more filters out to one file, provide the filters
as a vector to fcfwrite:
fcfwrite([hd hd1 hd2])
Version History
Introduced in R2011a
