Test number of arguments in TransformationFunction

symja_android_library/doc/functions/TransformationFunction.md

@@ -5,12 +5,6 @@ TransformationFunction(m)
 ```
 
 > represents a transformation.
-
-```
-TransformationFunction(phi, {0, 1}, {1, 0})
-```
-
-> gives a vertical shear by the angle `phi`.
  
 
 See

symja_android_library/matheclipse-core/src/main/java/org/matheclipse/core/builtin/TensorFunctions.java

@@ -1139,19 +1139,27 @@ private static class TransformationFunction extends AbstractFunctionEvaluator {
 
     @Override
     public IExpr evaluate(final IAST ast, EvalEngine engine) {
-      if (ast.head().isAST(S.TransformationFunction, 2)) {
-        IAST operator = (IAST) ast.head();
-        IExpr m = operator.arg1();
-        int dim = ast.arg1().isVector();
-        if (dim > 0) {
-          IAST v = (IAST) ast.arg1().normal(false);
-          // Take(m . Join(v, {1}), Length(v))
-          return F.Take(F.Dot(m, F.Join(v, F.list(F.C1))), F.ZZ(dim));
-        }
+      if (!ast.head().isAST(S.TransformationFunction, 2)) {
+        return F.NIL;
+      }
+
+      IAST operator = (IAST) ast.head();
+      IExpr m = operator.arg1();
+      if (!ast.isAST1()) {
+        // `1` called with `2` arguments; 1 argument is expected.
+        return Errors.printMessage(S.TransformationFunction, "argx",
+            F.List(ast, F.ZZ(ast.argSize())), engine);
+      }
+      int dim = ast.arg1().isVector();
+      if (dim > 0) {
+        IAST v = (IAST) ast.arg1().normal(false);
+        // Take(m . Join(v, {1}), Length(v))
+        return F.Take(F.Dot(m, F.Join(v, F.list(F.C1))), F.ZZ(dim));
       }
       return F.NIL;
     }
 
+
   }
 
   private static class TranslationTransform extends AbstractFunctionEvaluator {

symja_android_library/matheclipse-core/src/test/java/org/matheclipse/core/system/TensorTest.java

@@ -214,6 +214,9 @@ public void testTensorProduct() {
 
 
   public void testRotationTransform() {
+    check("TransformationFunction(#2)[Sequence()]", //
+        "TransformationFunction(#2)[]"); //
+
     check("RotationTransform(Pi).TranslationTransform({1, -1})", //
         "TransformationFunction(\n" //
             + "{{-1,0,-1},\n" //