Systematic additive and proportional distortions can interact. To illustrate this situation, column c) in Figure 2 shows the value between the index calculated for 2 vectors, with a given combination of distortions minus the value of the index calculated from the same vectors without bias. This only appears for a given correlation of. This graphical representation can help illustrate the sensitivity of an index for small changes in b and m. Most indices react in the same way, with the notable exception of HQ. The AC Ji-Gallo index may be higher (i.e. more compliance) with a combination of small distortions than without any bias. The moulded metal containers lacked the intrinsic rotational symmetry of the wheel ceramics, but also offered a similar opportunity to decorate their surfaces with patterns that appealed to those who used them. The ancient Chinese, for example, used symmetrical patterns in their bronze cast iron pieces as early as the 17th century BC. The bronze containers showed both a main bilateral pattern and a repetitive translated marginal image.  Symmetry (from the Greek, symmetry "denudation agreement, due ratio, disposition" refers to a harmonious and beautiful sense of relationship and balance.
  [a] In mathematics, "symmetry" has a more precise definition and is generally used to refer to an object that is invariant under certain transformations; including translation, reflection, rotation or scale.  Although these two meanings of "symmetry" can sometimes be dissected, they are complex and are therefore discussed together in this article. The interval cycles are symmetrical and therefore non-diatonic. However, a segment of seven pitches of C5 (the cycle of the fifth, which are harmonic with the cycle of four) will create the main diatonic scale. Cyclical progress in the works of romantic composers such as Gustav Mahler and Richard Wagner is linked to the cyclical tone sequences in the atonal music of modernists such as Barték, Alexander Skrjabin, Edgard Varese and the Viennese school. At the same time, these progressions indicate the end of the tone.   To calculate these new derivative indices, the relationship between X and Y must first be characterized, which then allows the calculation and, finally, that of δ. The theoretical relationship between X and Y is considered linear: . Willmott6 uses an ordinary regression to the smallest square to appreciate a and b. This may be acceptable if the X-Dataset is considered a reference, but not if one tries to get an agreement without taking a reference, because there is a violation of the symmetry between X and Y, i.e. a regression from X to Y does not correspond to that of Y to X.
To solve this problem, Ji-Gallo9 proposes to use a geometric medium functional relationship model (GMFR) 21.22, for which b and a are derived as follows: Sound lines or series of tone ranges that are invariant under retrograde are horizontally symmetrical, under vertical inversion.