Module:Utils: Difference between revisions

← Older edit Newer edit →

@@ Line 1: / Line 1: @@
 local p = {}
+-- evaluate input on error use default
+local function eval_num_arg(input, def_value)
+	local result = input
+	if type(input) ~= 'number' then
+		result = def_value
+		if type(input) == 'string' then
+			input = input:match("^%s*(.-)%s*$")
+			if string.len(input) > 0 then
+				result = tonumber(input)
+			end
+		end
+	end
+	return result
+end
 -- return logarithm base b of x
-function p.log(x, b)
+function p.log(frame)
-	b = b or 2 -- defaults to base 2 (octave) if b is omitted
+	-- x defaults to 0 if omitted
+	local x = eval_num_arg(frame.args[1], 0)
+	-- b defaults to 2 ("octave") if omitted
+	local b = eval_num_arg(frame.args[2], 2)
 	return math.log(x)/math.log(b)
 end
@@ Line 9: / Line 27: @@
 -- return x rounded to a precision of p decimal places
 function p.round(x, prec)
-	prec = prec or 3 -- default to 3 decimal places if prec is omitted
+	-- x defaults to 0 if omitted
+	local x = eval_num_arg(frame.args[1], 0)
+	-- prec defaults to 3 if omitted
+	local prec = eval_num_arg(frame.args[2], 3)
 	return math.floor(x*10^prec+0.5)/10^prec
 end
 return p