Module:Math: Difference between revisions

Module:Math (edit)

990 bytes added , 11 years ago

Add precision calculation

Anonymous user

@@ Line 1: / Line 1: @@
-local mathy = {}
+local z = {}
-function mathy.random( frame )
+function z.random( frame )
      first = tonumber(frame.args[1]) -- if it doesn't exist it's NaN, if not a number it's nil
      second = tonumber(frame.args[2])
@@ Line 13: / Line 13: @@
      return math.random()
 end
+function z.precision( frame )
+    return z._precision( frame.args[1] or frame.args.x or '0' )
+end
+-- Determines precision of a number using the string representation
+function z._precision( x )
+    x = string.upper( x )
+    local decimal = string.find( x, '.', 1, true )
+    local exponent = string.find( x, 'E', 1, true )
+    local result = 0;
+    if exponent ~= nil then
+        exponent = string.sub( x, exponent + 1 )
+        x = string.sub( x, 0, exponent )
+        result = result - tonumber( exponent )
+    end
+    if decimal ~= nil then
+        result = result + string.len( x ) - decimal
+        return result
+    end
+    local pos = string.len( x );
+    while x:byte(pos) == string.byte('0') do
+        pos = pos - 1
+        result = result - 1
+        if pos <= 0 then
+            return 0
+        end
+        if x:byte(pos) == string.byte('.') then
+            pos = pos - 1
+        end
+    end
+    return result
+end
+return z