symbol

meaning

$l_{\text{former},\text{tick-mark}}$

tick-mark length of former tick-mark

$\left(x_{\text{former},\text{center}},y_{\text{former},\text{center}}\right)$

Brightness barycenter center of former tick-mark

$D_{\text{former}}$

Distance between $\left(x_{\text{former},\text{center}},y_{\text{former},\text{center}}\right)$ and $\left(x_{\text{center}},y_{\text{center}}\right)$

${\theta }_{\text{former},\text{scale}}$

Angle of former tick mark on reference to coordinate origin $\left(x_{\text{center}},y_{\text{center}}\right)$

$\Delta {\theta }_{\text{former}}$

Difference between ${\theta }_{\text{former},\text{scale}}$ and its former tick mark