add sphear_fir_extract to get filter shape from power spectrum

sphear_fir_extract.m

@@ -0,0 +1,44 @@
+%%
+%% *SpHEAR Project
+%%
+%% sphear_fir_extract: extract W and XYZ filter shapes from B format response
+%%
+%% usage:
+%%   [] = sphear_fir_extract()
+%%
+%% Copyright 2016, Fernando Lopez-Lezcano, All Rights Reserved
+%% nando@ccrma.stanford.edu
+%%
+%%  This program is free software: you can redistribute it and/or modify
+%%  it under the terms of the GNU General Public License as published by
+%%  the Free Software Foundation, either version 3 of the License, or
+%%  (at your option) any later version.
+%%
+%%  This program is distributed in the hope that it will be useful,
+%%  but WITHOUT ANY WARRANTY; without even the implied warranty of
+%%  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+%%  GNU General Public License for more details.
+%%
+%%  You should have received a copy of the GNU General Public License
+%%  along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+function [W XYZ] = sphear_fir_extract(B, all, onaxis);
+
+  if (all == 1)
+    m = (1:16);
+  else
+    if (onaxis == 1)
+      m = [1,5,9,13];
+    else
+      m = [3, 7, 11, 15];
+    end
+  end
+  
+  %% extract average response shape for W
+  W = 1.0 ./ reshape(mean(B(m,1,:)), size(B(:,:,:))(3), 1);
+
+  %% extract average response shape for XYZ
+  XYZ = 1.0 ./ reshape(mean(mean(B(m, [2, 3, 4], :))), size(B(:,:,:))(3), 1);
+
+end
+