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Trapezoidal numerical integration

`Q = trapz(Y)`

`Q = trapz(X,Y)`

`Q = trapz(___,dim)`

`Q = trapz(`

returns
the approximate integral of `Y`

)`Y`

via the trapezoidal method with
unit spacing. The size of `Y`

determines the dimension
to integrate along:

If

`Y`

is a vector, then`trapz(Y)`

is the approximate integral of`Y`

.If

`Y`

is a matrix, then`trapz(Y)`

integrates over each column and returns a row vector of integration values.If

`Y`

is a multidimensional array, then`trapz(Y)`

integrates over the first dimension whose size does not equal 1. The size of this dimension becomes 1, and the sizes of other dimensions remain unchanged.

Use

`trapz`

and`cumtrapz`

to perform numerical integrations on discrete data sets. Use`integral`

,`integral2`

, or`integral3`

instead if a functional expression for the data is available.`trapz`

reduces the size of the dimension it operates on to 1, and returns only the final integration value.`cumtrapz`

also returns the intermediate integration values, preserving the size of the dimension it operates on.

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