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Diffstat (limited to 'macros/cell2sos.sci')
| -rw-r--r-- | macros/cell2sos.sci | 90 |
1 files changed, 38 insertions, 52 deletions
diff --git a/macros/cell2sos.sci b/macros/cell2sos.sci index 7cd657d..03e13be 100644 --- a/macros/cell2sos.sci +++ b/macros/cell2sos.sci @@ -9,61 +9,47 @@ // Last Modified : 3 Feb 2024 // Organization: FOSSEE, IIT Bombay // Email: toolbox@scilab.in -/* -Calling Sequence : - sos = cell2sos(cll) - [sos,g] = cell2sos(cll) -Description - sos = cell2sos(cll) generates a matrix sos containing the coefficients of the filter system described by the second-order section cell array cll. - [sos,g] = cell2sos(cll) also returns the scale gain g. - Second-order section cell-array representation, specified as a cell array. +function [s,g] = cell2sos(c) +// Calling Sequence : +// sos = cell2sos(cll) +// [sos,g] = cell2sos(cll) +// Description +// sos = cell2sos(cll) generates a matrix sos containing the coefficients of the filter system described by the second-order section cell array cll. +// [sos,g] = cell2sos(cll) also returns the scale gain g. +// Second-order section cell-array representation, specified as a cell array. +// Input Argument: +// For a filter system with L sections, specify 'cll' using this structure: +// * Cell array with L elements — For unity-gain filter systems. Each element of the cell +// array corresponds to a second-order section. The kth cell array element of 'cll' +// cll{k} = {[b_0k b_1k b_2k] [1 a_1k a_2k]} +// contains the coefficients from the kth second-order-section of the filter system H(z): +// H(z) = product(k=1 to L) H_k(z) +// = product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) +// * Cell array with L+1 elements — If the gain of the filter system is different from 1. +// The first element of 'cll' contains the system gains at the numerator (g_n) and at +// the denominator (g_d). Then, the function appends each element of the cell array for +// the corresponding second-order section. +// The first and the k+1th cell array element of 'cll' +// cll{1} = {g_n g_d} +// cll{k+1} = {[b_0k b_1k b_2k] [1 a_1k a_2k]} +// contain the system gain and the coefficients from the kth second-order section of +// the filter system H(z), respectively, such that: +// H(z) = (g_n/g_d) * product(k=1 to L) H_k(z) +// = (g_n/g_d) * product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) +// Output Argument: +// Second-order section representation, returned as an L-by-6 matrix, where L is the +// number of second-order sections. The matrix +// sos = [b_01 b_11 b_21 1 a_11 a_21] +// [b_02 b_12 b_22 1 a_12 a_22] +// [ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ] +// [b_0L b_1L b_2L 1 a_1L a_2L] +// represents the second-order sections of H(z): +// H(z) = g * product(k=1 to L) H_k(z) +// = g * product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) +// -Input Argument: - For a filter system with L sections, specify 'cll' using this structure: - - * Cell array with L elements — For unity-gain filter systems. Each element of the cell - array corresponds to a second-order section. The kth cell array element of 'cll' - - cll{k} = {[b_0k b_1k b_2k] [1 a_1k a_2k]} - - contains the coefficients from the kth second-order-section of the filter system H(z): - - H(z) = product(k=1 to L) H_k(z) - = product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) - - * Cell array with L+1 elements — If the gain of the filter system is different from 1. - The first element of 'cll' contains the system gains at the numerator (g_n) and at - the denominator (g_d). Then, the function appends each element of the cell array for - the corresponding second-order section. - - The first and the k+1th cell array element of 'cll' - - cll{1} = {g_n g_d} - cll{k+1} = {[b_0k b_1k b_2k] [1 a_1k a_2k]} - - contain the system gain and the coefficients from the kth second-order section of - the filter system H(z), respectively, such that: - - H(z) = (g_n/g_d) * product(k=1 to L) H_k(z) - = (g_n/g_d) * product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) - -Output Argument: - Second-order section representation, returned as an L-by-6 matrix, where L is the - number of second-order sections. The matrix - - sos = [b_01 b_11 b_21 1 a_11 a_21] - [b_02 b_12 b_22 1 a_12 a_22] - [ ⋮ ⋮ ⋮ ⋮ ⋮ ⋮ ] - [b_0L b_1L b_2L 1 a_1L a_2L] - - represents the second-order sections of H(z): - - H(z) = g * product(k=1 to L) H_k(z) - = g * product(k=1 to L) (b_0k + b_1k*z^(-1) + b_2k*z^(-2))/(1 + a_1k*z^(-1) + a_2k*z^(-2)) -*/ -function [s,g] = cell2sos(c) if(argn(2)~=1) then error("cell2sos: Wrong number of input arguments"); end |