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--- doc:user:general:fonctions [2015/01/07 14:52] – boman
+++ doc:user:general:fonctions [2025/04/04 13:57] (current) – [PieceWiseLinearFunction] papeleux
@@ Line 1: / Line 1: @@
-====== Functions ======
+====== Functions y=f(t) ======
-Functions are quite useful to describe how some parameters evolve, over time for example. They can be used to [[doc:user:conditions:displacements|set displacements]] or to define [[doc:user:elements:volumes:start|hardening laws]].
+Functions are quite useful to describe how some parameters evolve, over time for example. They can be used to [[doc:user:conditions:displacements|prescribe displacements]] or to define [[doc:user:elements:volumes:start|hardening laws]].
 ===== PieceWiseLinearFunction =====
@@ Line 21: / Line 22: @@
 __Remark:__ As can be seen above, the first and last segments are extrapolated if a value of the function is required outside its domain.
+<note important>
+Data must be defined in a STRICTLY increasing abcissae order ...
+AND at least 2 points has to be defined...
+</note>
+===== CyclicPieceWiseLinearFunction =====
+The ''CyclicPieceWiseLinearFunction'' allows to duplicate infinitely  a ''PieceWiseLinearFunction''.
+{{ :doc:user:cyclicpiecewiselinearfunction.png?600 |}}
+constrains are applied on Data :
+  - the first abcisse must be equal to 0.0 (abs1 = 0.0)
+  - the cycle must be closed (ord1 = ordLast)
 ===== PythonOneParameterFunction =====
-If a function is mathematically too complex to be defined with a ''PieceWiseLinearFunction'', it can be defined analytically, with the function ''PythonOneParameterFunction''.
+If a function is mathematically too complex to be defined with a ''PieceWiseLinearFunction'', it can be defined analytically, with a ''PythonOneParameterFunction'' object.
-The goal is to give as argument a Python function as ''OneParameterFunction''.
+  def f(x):
+      [function calculating y=f(x)]
+      return y
+  fct1 = PythonOneParameterFunction(f)
 For example, this is used to:
@@ Line 38: / Line 56: @@
     fct1 = PieceWiseLinearFunction()
-    fct1.setdata(0,0)
+    fct1.setData(0,0)
-    fct1.setdata(1,1)
+    fct1.setData(1,1)
 can be also defined with a classical python function:
@@ Line 53: / Line 71: @@
 ===== Advanced use =====
-{{:doc:user:ico-advanced.png?25 |Advanced}}
+{{:doc:user:ico-advanced.png?40 |Advanced}}
 The value can also be displayed for each estimation, and a more complex function can also be defined using all Python tools. For example, a load function can be first defined with a parabola, then with a straight line, the change between these two being controlled by an conditional structure.