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In this tutorial you will perform an uncertainty study on the fruit tree model. The goal is to find out how PCP101 is taken up via root uptake by apple trees.
Concentration in soil
|Time(d)||Value (mg kg dw-1)|
|Time(d)||Value (mm d-1)|
Temperature of air
The information we have about the distribution of possible values for a parameter is described using a PDF. Common PDF's include the normal distribution, the uniform distribution and their logarithmic counterparts (lognormal, loguniform), but there are many others.
Almost all probability density functions require some information from you. Some distributions allow you to provide the same information but using different information sets; the normal distribution can be defined using either the mean + standard deviation or by entering two percentiles.
The written representation of a PDF is name(arg1=x, arg2=y). It can be difficult to remember the name of all the functions and their arguments. Therefore it is more common to use the editor when entering PDFs. The PDF editor appears when you click a field which requires a distribution.
The familiar bell shape of the normal distribution is displayed in the editor. The buttons on the left allow you to change the graph to, instead of the PDF, show the CDF, survival function, hazard function or cumulative hazard function.
The PDF Editor has some tools you can use to perform some statistical calculations on the function.
The properties tool will show you statistical information about the on the currently selected function.
The calculator tool let you make some quick calculations using the selected function.
The chart tool highlights the percentiles entered in the calculation tool.