## On the Subject of Creating Coordinates

Coordinate creation causes confusion commonly.

#### Table 1: grid size formats

Format | How to interpret | |||||||||||||||
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|

n
| 9 | 3×3 | 15 | 5×3 | 21 | 7×3 | 25 | 5×5 | 35 | 7×5 | 49 | 7×7 | ||||

(n)
| 9 | 3×3 | 15 | 3×5 | 21 | 3×7 | 25 | 5×5 | 35 | 5×7 | 49 | 7×7 | ||||

w×h | w is the width, h the height of the grid. | |||||||||||||||

h by w | h is the height, w the width of the grid. | |||||||||||||||

n*h | n is the total size of the grid, w = n ÷ h. | |||||||||||||||

n : w | n is the total size of the grid, h = n ÷ w. |

#### Table 2: grid location formats

[c,r] | Top-left is [0,0]. | c rletter number | Top-left is A1. |
---|---|---|---|

<r, c> | Top-left is <0, 0>. | r, c | Top-left is 1, 1. |

(c,r) | Bottom-left is (0,0). | c-rletter-number | Bottom-left is A-1. |

“r, c” | Bottom-left is “0, 0”. | r/c | Bottom-left is 1/1. |

[x] | Traverse right then down[1]; Top-left is [0]. | xth | Traverse right then down[1]; Top-left is 1st. |

#x | Traverse right then up[2]; Bottom-left is #1. | 四十七 | Traverse down then left[3]; top-right is 一. |

#### Table 3: Chinese numerals

一 | 1 | 二 | 2 | 三 | 3 | 四 | 4 | 五 | 5 |
---|---|---|---|---|---|---|---|---|---|

六 | 6 | 七 | 7 | 八 | 8 | 九 | 9 | 十 | 10 |

[1] Scanline order, also known as reading order, starts at the top-left, moves right across the row, and then continues likewise with each row from top to bottom.

[2] Cartesian order, also known as geometric order, starts at the bottom-left, moves right across the row, and then continues likewise with each row from bottom to top.

[3] Traditional Chinese reading order starts at the top-right, moves down the column, and then continues likewise with each column from right to left.