1sem matlab 05

1sem/octave/05/calc_info.m

@@ -0,0 +1,25 @@
+function [b,n] = calc_info(msg, alph, alph_p)
+  l_alph = length(alph);
+  l_alph_p = length(alph_p);
+  l_msg = length(msg);
+  if l_alph ~= l_alph_p;
+    error("[ERR] length(alph) != length(alph_p) (%d != %d)", l_alph, l_alph_p)
+  endif
+  
+  b = 0;
+  for i = 1:l_msg
+    flag = false;
+    for j = 1:l_alph
+      if msg(i) == alph(j)
+        flag = true;
+        b -= log(alph_p(j));
+        break
+      endif
+    endfor
+    if ~flag 
+      warning("[WARN] Symbol '%s' (at pos. %d from msg) not found in alphabet", msg(i), i)
+    endif
+  endfor
+  
+  n = l_msg * log2(l_alph);
+endfunction