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#### 7.1.6 `1d`, `2d`, ...: Isotropic Cartesian Matching

```matcher=1d values*='<x>'
params='<error>'
tuning='<bin-factor>'```
`values*`:
• `x`: Cartesian co-ordinate #1
`params`:
• `error`: Maximum Cartesian separation for match
`tuning`:
• `bin-factor`: Scaling factor to adjust bin size; larger values mean larger bins

```matcher=2d values*='<x> <y>'
params='<error>'
tuning='<bin-factor>'```
`values*`:
• `x`: Cartesian co-ordinate #1
• `y`: Cartesian co-ordinate #2
`params`:
• `error`: Maximum Cartesian separation for match
`tuning`:
• `bin-factor`: Scaling factor to adjust bin size; larger values mean larger bins

The `1d` matcher compares positions in 1-dimensional Cartesian space. Rows are considered to match if their `x` column values differ by no more than `error`.

The `2d` matcher compares postions in 2-dimensional Cartesian space. Rows are considered to match if the difference in their (`x`,`y`) positions reckoned using Pythagoras is less than `error`.

Matching in any number of Cartesian dimensions can be done by extending this syntax in the obvious way.

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Next: 2d_anisotropic, ...: Anisotropic Cartesian Matching
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