diff --git a/src/math/pievaluator.cpp b/src/math/pievaluator.cpp
index f116ea24..b105bc6d 100755
--- a/src/math/pievaluator.cpp
+++ b/src/math/pievaluator.cpp
@@ -98,7 +98,8 @@
  * * y0(x) - Bessel function second kind order 0
  * * y1(x) - Bessel function second kind order 1
  * * yn(x, n) - Bessel function second kind order n
- * * random(s, f) - regular random number in range [s, f]
+ * * random(s, a) - regular random with shift s and amp a
+ * * randomn(s, a) - normalize random with shift s and amp a
  * * min(x0, x1, ...) - minimum of x0, x1, ...
  * * max(x0, x1, ...) - maximum of x0, x1, ...
  * * clamp(x, a, b) - trim x on range [a, b]
@@ -123,6 +124,7 @@ PIEvaluatorContent::PIEvaluatorContent() {
 	addFunction("arctg", 1);
 	addFunction("arcctg", 1);
 	addFunction("random", 2);
+	addFunction("randomn", 2);
 	addFunction("sin", 1);
 	addFunction("cos", 1);
 	addFunction("ctg", 1);
@@ -216,6 +218,7 @@ PIEvaluatorTypes::BaseFunctions PIEvaluatorContent::getBaseFunction(const PIStri
 	if (name == "arcctg") return PIEvaluatorTypes::bfArcctg;
 	if (name == "exp") return PIEvaluatorTypes::bfExp;
 	if (name == "random") return PIEvaluatorTypes::bfRandom;
+	if (name == "randomn") return PIEvaluatorTypes::bfRandomn;
 	if (name == "sh") return PIEvaluatorTypes::bfSh;
 	if (name == "ch") return PIEvaluatorTypes::bfCh;
 	if (name == "th") return PIEvaluatorTypes::bfTh;
@@ -1160,10 +1163,11 @@ inline void PIEvaluator::execFunction(const PIEvaluatorTypes::Instruction & ci)
 		tmpvars[oi].value = value(ci.operators[0]).real() > 0. ? complexd_1 : complexd_0;
 		break;
 	case PIEvaluatorTypes::bfRandom:
-		tmp = static_cast<ldouble>(rand()) / RAND_MAX;
-		stmp = value(ci.operators[1]) - value(ci.operators[0]);
-		tmpvars[oi].value = value(ci.operators[0]) + tmp * stmp;
+		tmpvars[oi].value = value(ci.operators[0]) + randomd() * value(ci.operators[1]);
 		break;
+	case PIEvaluatorTypes::bfRandomn:
+		tmpvars[oi].value = randomn(value(ci.operators[0]).real(), value(ci.operators[1]).real());
+	break;
 	default: break;
 	}
 }
diff --git a/src/math/pievaluator.h b/src/math/pievaluator.h
index f840b1ae..2819ce52 100755
--- a/src/math/pievaluator.h
+++ b/src/math/pievaluator.h
@@ -38,7 +38,8 @@ namespace PIEvaluatorTypes {
 	};
 	enum BaseFunctions {bfUnknown, bfSin, bfCos, bfTg, bfCtg,
 						bfArcsin, bfArccos, bfArctg, bfArcctg,
-						bfExp, bfRandom, bfSh, bfCh, bfTh, bfCth,
+						bfExp, bfRandom, bfRandomn,
+						bfSh, bfCh, bfTh, bfCth,
 						bfSqrt, bfSqr, bfPow, bfAbs,
 						bfLn, bfLg, bfLog, bfSign,
 						bfIm, bfRe, bfArg, bfLen, bfConj,