Data update

Task/Statistics-Basic/Loglan82/statistics-basic.loglan82

@@ -0,0 +1,71 @@
+(* Statistics/Basic *)
+
+block
+
+  unit basic_stats: procedure (sample_size: integer);
+  var
+    r: arrayof real,
+    sum, scale, mean, diff, sd: real,
+    h: arrayof integer,
+    h_sum, i, j, adj: integer;
+  begin
+    if sample_size < 1 then return fi;
+
+    array r dim (1 : sample_size);
+    array h dim (0 : 9); (* all zero by default *)
+    sum := 0.0;
+    h_sum := 0;
+    (* Generate 'sample_size' random numbers in the interval [0, 1).
+      Calculate their sum and in which box they will fall when drawing
+      the histogram *)
+    for i := 1 to sample_size
+    do
+      r(i) := random;
+      sum := sum + r(i);
+      h(entier(r(i) * 10)) := h(entier(r(i) * 10)) + 1
+    od;
+    for i := 0 to 9 do h_sum := h_sum + h(i) od;
+    (* Adjust one of the h() values if necessary to ensure h_sum = sample_size *)
+    adj := sample_size - h_sum;
+    if adj =/= 0
+    then
+      for i := 0 to 9
+      do
+        h(i) := h(i) + adj;
+        if h(i) >= 0 then exit fi;
+        h(i) := h(i) - adj
+      od;
+    fi;
+    mean := sum / sample_size;
+
+    sum := 0.0;
+    (* Now calculate their standard deviation *)
+    for i := 1 to sample_size
+    do
+      diff := r(i) - mean;
+      sum := sum + diff * diff
+    od;
+    sd := sqrt(sum / sample_size);
+
+    (* Draw a histogram of the data with interval 0.1.
+      If sample size > 500 then normalize histogram to 500. *)
+    scale := 1.0;
+    if sample_size > 500 then scale := 500.0 / sample_size fi;
+    writeln("Sample size", sample_size);
+    writeln("  Mean ", mean: 8: 6, "  SD ", sd: 8: 6);
+    for i := 0 to 9
+    do
+      write("  ", i / 10.0: 4: 2, " : ", h(i): 5, " ");
+      for j := 1 to entier(h(i) * scale + .5) do write("*") od;
+      writeln
+    od;
+  end basic_stats;
+
+begin
+  call basic_stats(100);
+  writeln;
+  call basic_stats(1000);
+  writeln;
+  call basic_stats(10000);
+  writeln;
+end;