1. Probabilistic tools in OpenEarth
Example with Van der Meer formula
Kees den Heijer, TU Delft & Deltares

2. Overview Probabilistic calculation Relevant Matlab tools
Stochastic variables
Limit state function (Z-function)
Reliability method (FORM, Monte Carlo)
Relevant Matlab tools
OpenEarthTools CT4310 release as zip-file
OpenEarthTools full version via subversion

3. Stochast variable Structure with fields: Name Distr Params
Unique name for each stochastic variable
Distr
Functionhandle of distribution function
Params
Parameters in cell-array as input for the corresponding distribution function
propertyName
Indicate how to parse variable to z-function

4. Distribution should be matlab functionhandle
Stochast variable
Names are custom
Distribution should be matlab functionhandle
Params are second and further input arguments of the distribution function
Distr
Params

5. Available distribution functions
Functionhandle
Parameters
Normal
@norm_inv
mu, sigma
Exponential
@exp_inv
lambda, epsilon
Triangular
@trian_inv
a, b, c
Lognormal
@logn_inv
Uniform
@unif_inv
a, b
Conditional Weibull
@conditionalWeibull
omega, rho, alpha, sigma
Deterministic
@deterministic x

6. Limit state function This should be created as separate function
Input arguments:
samples : specified as propertyName-propertyValue pairs
Output argument:
z : z-values corresponding to the x-values

7. Limit state function
Calculate Z

8. Run calculation General Monte Carlo Additional settings:
Specify stochast variable with: ‘stochast’, stochast_variable
Specify z-function with:
Monte Carlo
Specify number of samples with: ‘NrSamples’, 1e4
Additional settings:
Next arguments are optional combinations of keywords and corresponding values (propertyName-propertyValue pairs)

9. Run calculation

10. Monte Carlo defaults

11. FORM defaults

12. Preparation Release with relevant tools available via Blackboard
Download and unzip the file CT4310_release.zip
Start Matlab
Activate tools by running: \CT4310_release\oetsettings.m

13. Example calculation
Example calculation with Van der Meer formula available under:

14. FAQ
Only the Monte Carlo output is available, how do I get the FORM results?
Monte Carlo seems to work properly, but FORM gives an error.

15. Only the Monte Carlo output is available, how do I get the FORM results? (1)

16. Only the Monte Carlo output is available, how do I get the FORM results? (2)

17. Monte Carlo seems to work properly, but FORM gives an error.
This message means that complex numbers are found by the z-function.
Solution: check whether your z-function probably in an unfavorable combination of stochastic variable values could lead to complex numbers…
Please note: if so, although Monte Carlo still gives a result, this is not reliable.

18. Full OpenEarthTools repository
A wide variety of tools
Including the tools relevant for this assignment
Matlab and other languages
Useful for MSc thesis project
Useful for your future job
Requirements:
Username and password: register at
Subversion client (e.g. TortoiseSVN)
About 1Gb disk space

19. Delft3D

20. JarKus transects

21. OpenEarth.nl