Function

class Function

General purpose function calculator using real numbers. It can parse mathematical expression defining a function and evaluate it and/or its derivative for specified variable values.You can assign expressions of the form:: f(c0, c1, ..., cM, x0, x1, ..., xN, y0,..., yP )

where ci's are constants and xi's and yi's are variables.The constants must be defined before setting the expression and variables are connected via messages. The constants can have any name, but the variable names must be of the form x{i} or y{i} where i is increasing integer starting from 0. The variables can be input from other moose objects. Such variables must be named x{i} in the expression and the source field is connected to Function.x[i]'s input destination field. In case the input variable is not available as a source field, but is a value field, then the value can be requested by connecting the requestOut message to the get{Field} destination on the target object. Such variables must be specified in the expression as y{i} and connecting the messages should happen in the same order as the y indices. This class handles only real numbers (C-double). Predefined constants are: pi=3.141592..., e=2.718281...

proc

void (shared message field) This is a shared message to receive Process messages from the scheduler objects.The first entry in the shared msg is a MsgDest for the Process operation. It has a single argument, ProcInfo, which holds lots of information about current time, thread, dt and so on. The second entry is a MsgDest for the Reinit operation. It also uses ProcInfo.

getValue()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

getRate()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

getDerivative()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setMode()

(destination message field) Assigns field value.

getMode()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setExpr()

(destination message field) Assigns field value.

getExpr()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setNumVars()

(destination message field) Assigns field value.

getNumVars()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setNumX()

(destination message field) Assigns number of field entries in field array.

getNumX()

(destination message field) Requests number of field entries in field array.The requesting Element must provide a handler for the returned value.

setC()

(destination message field) Assigns field value.

getC()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setIndependent()

(destination message field) Assigns field value.

getIndependent()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

process()

(destination message field) Handles process call, updates internal time stamp.

reinit()

(destination message field) Handles reinit call.

requestOut

PSt6vectorIdSaIdEE (source message field) Sends request for input variable from a field on target object

valueOut

double (source message field) Evaluated value of the function for the current variable values.

rateOut

double (source message field) Value of time-derivative of the function for the current variable values

derivativeOut

double (source message field) Value of derivative of the function for the current variable values

value

double (value field) Result of the function evaluation with current variable values.

rate

double (value field) Derivative of the function at given variable values. This is computed as the difference of the current and previous value of the function divided by the time step.

derivative

double (value field) Derivative of the function at given variable values. This is calulated using 5-point stencil <http://en.wikipedia.org/wiki/Five-point_stencil> at current value of independent variable. Note that unlike hand-calculated derivatives, numerical derivatives are not exact.

mode

unsigned int (value field) Mode of operation:

1: only the function value will be sent out. 2: only the derivative with respect to the independent variable will be sent out. 3: only rate (time derivative) will be sent out. anything else: all three, value, derivative and rate will be sent out.

expr

string (value field) Mathematical expression defining the function. The underlying parser is muParser. In addition to the available functions and operators from muParser, some more functions are added.

Functions Name args explanation sin 1 sine function cos 1 cosine function tan 1 tangens function asin 1 arcus sine function acos 1 arcus cosine function atan 1 arcus tangens function sinh 1 hyperbolic sine function cosh 1 hyperbolic cosine tanh 1 hyperbolic tangens function asinh 1 hyperbolic arcus sine function acosh 1 hyperbolic arcus tangens function atanh 1 hyperbolic arcur tangens function log2 1 logarithm to the base 2 log10 1 logarithm to the base 10 log 1 logarithm to the base 10 ln 1 logarithm to base e (2.71828...) exp 1 e raised to the power of x sqrt 1 square root of a value sign 1 sign function -1 if x<0; 1 if x>0 rint 1 round to nearest integer abs 1 absolute value min var. min of all arguments max var. max of all arguments sum var. sum of all arguments avg var. mean value of all arguments rand 1 rand(seed), random float between 0 and 1,

if seed = -1, then a 'random' seed is created.

rand2 3 rand(a, b, seed), random float between a and b,

if seed = -1, a 'random' seed is created using either by random_device or by reading system clock

Operators Op meaning priority = assignment -1 && logical and 1 || logical or 2 <= less or equal 4 >= greater or equal 4 != not equal 4 == equal 4 > greater than 4 < less than 4 + addition 5 - subtraction 5 * multiplication 6 / division 6 ^ raise x to the power of y 7 % floating point modulo 7

?: if then else operator C++ style syntax

numVars

unsigned int (value field) Number of variables used by Function.

independent

string (value field) Index of independent variable. Differentiation is done based on this. Defaults to the first assigned variable.

c

string,double (lookup field) Constants used in the function. These must be assigned before specifying the function expression.

class GammaRng

Gamma distributed random number generator.

setAlpha()

(destination message field) Assigns field value.

getAlpha()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

setTheta()

(destination message field) Assigns field value.

getTheta()

(destination message field) Requests field value. The requesting Element must provide a handler for the returned value.

alpha

double (value field) Parameter alpha of the gamma distribution.

theta

double (value field) Parameter theta of the Gamma distribution.