pybricks.geometry.Matrix: fix missing scale in subscr

Author: laurensvalk

pybricks/geometry/pb_type_matrix.c

@@ -473,7 +473,7 @@ STATIC mp_obj_t pb_type_Matrix_subscr(mp_obj_t self_in, mp_obj_t index_in, mp_ob
         }
 
         // Return result
-        return mp_obj_new_float_from_f(self->data[idx]);
+        return mp_obj_new_float_from_f(self->scale * self->data[idx]);
     }
     return MP_OBJ_NULL;
 }

tests/ev3dev/geometry/matrix.py

@@ -22,6 +22,10 @@
 print("A * 3 =", A * 3)
 print("3 * A =", 3 * A)
 
+# Reading elements
+print("B[0, 1] =", B[0, 1])
+print("B.T[0, 1] =", B.T[0, 1])
+
 # Vector basics
 b = vector(3, 4, 0)
 c = b.T

tests/ev3dev/geometry/matrix.py.exp

@@ -44,6 +44,8 @@ A * 3 = Matrix([
     [  12.000,   15.000,   18.000],
     [  21.000,   24.000,   27.000],
 ])
+B[0, 1] = -2.0
+B.T[0, 1] = -4.0
 b = vector(3, 4, 0) = Matrix([
     [   3.000],
     [   4.000],