# Add a trend to a process¶

In this basic example we are going to add a trend to a process.

The TrendTransform class enables to create a new process Y from a process X (no hypothesis on X needed):

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from __future__ import print_function
import openturns as ot
import math as m

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# Create a process
grid = ot.RegularGrid(0.0, 0.1, 10)
amplitude=[5.0]
scale=[0.2]
covModel = ot.ExponentialModel(scale, amplitude)
X = ot.GaussianProcess(covModel, grid)

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# Draw a sample
sample = X.getSample(6)
sample.setName('X')
sample.drawMarginal(0)

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# Define a trend function
f = ot.SymbolicFunction(['t'], ['30*t'])
fTrend = ot.TrendTransform(f, grid)

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# Add it to the process
Y = ot.CompositeProcess(fTrend, X)
Y.setName('Y')

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# Draw a sample
sample = Y.getSample(6)
sample.setName('Y')
sample.drawMarginal(0)

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