# Dashboard: wheelPixels

```       Name: wheelPixels                                             [Show more]
Type: Variable
Category: Dashboard
Summary: The number of pixels in the longest axis for the steering wheel
line at various points in a quadrant
Deep dive: Trigonometry
Context: See this variable in context in the source code
References: This variable is used as follows:
* UpdateDashboard uses wheelPixels

This table contains values that are used to calculate the coordinates of the
end of the line on the steering wheel.

The contents of the table are very close to the following (the values from
the following calculation are shown in the comments below - they are close,
but not quite a perfect match, so I haven't got this exactly right):

FOR I%, 0, 37
EQUB INT(0.5 + 53 * COS((PI/4) * I% / 42))
NEXT

This gives the length of the adjacent side of a right-angled triangle, with a
hypotenuse of length 53, and an angle ranging from 0 to PI/4 (i.e. one
eighth of a circle), split up into 42 points per eighth of a circle (so the
table's 38 points cover just less than an eighth of a circle).

In other words, if we have a clock whose centre is at the origin, then this
table contains the x-coordinate of the end of a clock hand of length 53 as it
moves from 3 o'clock to half past 4.

.wheelPixels

EQUB 53                \ INT(0.5 + 53.00) = 53
EQUB 53                \ INT(0.5 + 52.99) = 53
EQUB 53                \ INT(0.5 + 52.96) = 53
EQUB 53                \ INT(0.5 + 52.92) = 53
EQUB 53                \ INT(0.5 + 52.85) = 53
EQUB 53                \ INT(0.5 + 52.77) = 53
EQUB 53                \ INT(0.5 + 52.67) = 53
EQUB 53                \ INT(0.5 + 52.55) = 53
EQUB 52                \ INT(0.5 + 52.41) = 52
EQUB 52                \ INT(0.5 + 52.25) = 52
EQUB 52                \ INT(0.5 + 52.08) = 52
EQUB 52                \ INT(0.5 + 51.88) = 52
EQUB 52                \ INT(0.5 + 51.67) = 52
EQUB 52                \ INT(0.5 + 51.44) = 51 (doesn't match)
EQUB 51                \ INT(0.5 + 51.19) = 51
EQUB 51                \ INT(0.5 + 50.93) = 51
EQUB 51                \ INT(0.5 + 50.65) = 51
EQUB 50                \ INT(0.5 + 50.34) = 50
EQUB 50                \ INT(0.5 + 50.03) = 50
EQUB 50                \ INT(0.5 + 49.69) = 50
EQUB 49                \ INT(0.5 + 49.34) = 49
EQUB 49                \ INT(0.5 + 48.97) = 49
EQUB 48                \ INT(0.5 + 48.58) = 49 (doesn't match)
EQUB 48                \ INT(0.5 + 48.17) = 48
EQUB 47                \ INT(0.5 + 47.75) = 48 (doesn't match)
EQUB 47                \ INT(0.5 + 47.31) = 47
EQUB 46                \ INT(0.5 + 46.86) = 47 (doesn't match)
EQUB 46                \ INT(0.5 + 46.39) = 46
EQUB 45                \ INT(0.5 + 45.90) = 46 (doesn't match)
EQUB 45                \ INT(0.5 + 45.40) = 45
EQUB 44                \ INT(0.5 + 44.88) = 45 (doesn't match)
EQUB 44                \ INT(0.5 + 44.34) = 44
EQUB 43                \ INT(0.5 + 43.79) = 44 (doesn't match)
EQUB 42                \ INT(0.5 + 43.22) = 43 (doesn't match)
EQUB 41                \ INT(0.5 + 42.64) = 43 (doesn't match)
EQUB 40                \ INT(0.5 + 42.05) = 42 (doesn't match)
EQUB 39                \ INT(0.5 + 41.44) = 41 (doesn't match)
EQUB 38                \ INT(0.5 + 40.81) = 41 (doesn't match)
```