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Polynomial Control Systems (2014)

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4.3.1 Left and Right Coprime Tests

The coprimeness tests illustrated in Example 4.3 can be carried out automatically by using the functions LeftCoprime and RightCoprime.

Testing the coprimeness.

Make sure the application is loaded.

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Here are the matrices N(s) and D(s) of a right matrix-fraction model of a system.

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This constructs a block matrix  .

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This is its Smith form.

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Since the leading 2 × 2 block of the Smith form is equal to the identity matrix I2, the two polynomial matrices describing the right matrix-fraction model are relatively right prime, or coprime, and hence no lower-order version exists that would create the same transfer-function matrix.

Here is the same result obtained at once using the function RightCoprime.

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Here is the corresponding right matrix-fraction object.

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You can also apply the function RightCoprime directly to the matrix-fraction object.

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Here is a LeftMatrixFraction object.

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You can equally apply the function LeftCoprime directly to the matrix-fraction object.

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