remove the special case for A2B matrix calculation from the code

calibration/src/sphear_design_example.m

@@ -55,6 +55,8 @@ sphear_af_calibrate((1:16), 0.0045, 0.001);
 
 sphear_octa_af_calibrate((1:16), 0.004, 0.001);
 
+%% now we start the calibration process
+
 %% read all the calibrated A-format files
 [AF, FS] = sphear_af_read((1:16));
 
@@ -80,8 +82,6 @@ sphear_plot_r(R, 0);
 
 [A2B, PV, COND] = sphear_calculate_a2b(R);
 
-[A2B, PV, COND] = sphear_octa_calculate_a2b(R);
-
 %% generate a B-format signal using the A-format signal and the static A to B matrix
 
 [BF] = sphear_af_to_bf(AF, A2B);