# Test a matrix of contrast coefficients for pairwise orthogonality

### Description

This function tests all pairwise contrast coefficients for orthogonality. The function tells the user which pair of contrasts are not orthogonal.

### Usage

1 |

### Arguments

`contr` |
A matirx, wiht k-1 rows (one for each contrast) and k columns one for each level of a factor. |

`round` |
To test if the sum of the products of the coefficients is zero the sum is rounded using this value as digits argument for round. |

### Details

For all pairs of contrasts coefficients the sum of the products of the coefficients is calculated and compared if it is zero or not.

### Value

a logical

### Note

There are more elegant solutions to this problem but this one tells the user which pairs of contrasts are not orthogonal.

### Author(s)

### References

none

### See Also

`mancontr`

### Examples

1 2 3 4 5 |

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