Package com.openinventor.imageviz.nodes.measures

Class SoDataMeasureCustom

  • All Implemented Interfaces:
    SafeDisposable
    public class SoDataMeasureCustom
extends SoDataMeasure
    class to define a custom measure. A custom measure is defined by a string formula that can use other custom or predefined measure. It must have a unique name. 

     // Example of code to define a custom measure using two predefined measure and
 // defined as the ratio of the Volume/Area.
 SoDataMeasureCustom* myMeasure1 = new SoDataMeasureCustom();
 myMeasure1->measureName = "myMeasure1";
 myMeasure1->formula = SoDataMeasurePredefined.getName(SoDataMeasurePredefined.VOLUME) + "/" + SoDataMeasurePredefined.getName(SoDataMeasurePredefined.AREA);
 
 // myMeasure1 can in turn be used to define an other custom measure, define as 2*myMeasure1
 SoDataMeasureCustom* myMeasure2 = new SoDataMeasureCustom();
 myMeasure2->measureName = "myMeasure2";
 myMeasure2->formula = myMeasure1.getMeasureName() + "*2";

    Custom formula syntax

    Custom formula syntax is checked before acceptation by ImageViz. Custom measure formula and custom filter formula follow the same basic rules and can use the same set of predefined functions. Custom measure formula must be a numerical value whereas custom filter formula must be a logical value to be accepted. Formula can be composed of constants, operators, functions and variables (native measures and custom measures).


    Remarks :

    • The following (unless specified) constants, operators, functions and variables are unsensitive to case and can be used both with custom measures and custom filters.
    • The following (unless specified) operators and functions are unsensitive to spaces. Constants and variables must not be directely attached to alpha numerical symbols.


    The following syntax can be used to define a formula :

    Basic operators

    () : brackets allowing to group elements and to modify operators precedence
    example : (2 + 3)*4

    + : unary arithmetic operator [plus]
    example : + a

    - : unary arithmetic operator [minus]
    example : - b

    + : binary arithmetic operator [plus]
    example : a + b

    - : binary arithmetic operator [minus]
    example : a - b

    * : binary arithmetic operator [multiply]
    example : a * b

    / : binary arithmetic operator [divide]
    example : a / b
    remark : a division by 0 returns the value 0 in order to avoid exceptions.

    ** : binary arithmetic operator [pow]
    example : a ** b

    ! : unary logical operator [not]
    example : !(a>b)

    && : or And : binary logical operator [and]
    example : (a>b) && (a<c)
    example : (a>c) And (a<c)
    remark : And : operator must not be directely attached to alpha numerical symbols.

    || : or Or : binary logical operator [or]
    example : (a>b) || (a<c)
    example : (a>b) Or (a<c)
    remark : Or : operator must not be directely attached to alpha numerical symbols.

    == : comparison operator (logical and arithmetic) [equal]
    example : a==b
    example : true==true

    != : comparison operator (logical and arithmetic) [different]
    example : a != b
    example : true != false

    < : arithmetic comparison operator [strictly inferior]
    example : a < b

    <= : arithmetic comparison operator [less]
    example : a<= b

    > : arithmetic comparison operator [strictly superior]
    example : a > b

    >= : arithmetic comparison operator [superior]
    example : a >= b

    Constant values

    Pi : , the pi constant
    example : 3 * Pi

    E : , the Euler's constant
    example : 2 * E

    True : the true boolean value
    example : (3<Pi)==True

    False : the false boolean value
    example : (3>Pi)==False

    NbFeret : distribution size for feret measures
    example : 3*NbFeret

    gx : , gy : and gz : image X, Y and Z size associated to measure
    example : 3*gx
    remark : not available for custom filters

    cx : , cy : and cz : stand for pixel real size according to calibration
    example : 3*cx
    remark : not available for custom filters

    Functions

    Abs : absolute value of a numerical value
    example : abs(a)

    Sqrt : square root value of a numerical value
    example : sqrt(a)
    remark : a must be positive or null

    Exp : exponential value of a numerical value
    example : exp(a)

    Log : natural logarithm value of a numerical value
    example : log(a)
    remark : a must be strictly positive

    Cos : cosine value of a numerical value
    example : cos(a)

    Sin : sine value of a numerical value
    example : sin(a)

    Tan : tangent value of a numerical value
    example : tan(a)

    ACos : arccosine value of a numerical value
    example : acos(a)
    remark : a must within range [-1, 1]

    ASin : sine arcvalue of a numerical value
    example : asin(a)
    remark : a must within range [-1, 1]

    ATan : arctangent value of a numerical value
    example : atan(a)

    ATan2 : arctangent value of a 2d point
    example : atan(y, x)

    CosH : hyperbolic cosine value of a numerical value
    example : cosh(a)

    SinH : hyperbolic sine value of a numerical value
    example : sinh(a)

    TanH : hyperbolic tangent value of a numerical value
    example : tanh(a)

    Min : retrieve minimum value of a variable sized set of numerical values
    example : min(a, b, c, d)

    Max : retrieve maximum value of a variable sized set of numerical values
    example : max(a, b, c, d, e)

    Avg : retrieve mean value of a variable sized set of numerical values
    example : avg(a, b, c)

    Median : retrieve median value of a variable sized set of numerical values
    example : median(a, b, c, d)

    Sum : compute the sum of a variable sized set of numerical values
    example : sum(a, b, c)

    Sum : compute the product of a variable sized set of numerical values
    example : product(a, b, c, d, e)

    If : : conditional evaluation of an expression
    example : if(predicat, value_true, value_false)
    remark : Each member of a conditional expression is systematically evaluated even if it is not supposed to be reached by the condition. Thus an instruction can raise an error even if the condition is supposed to prevent invalid evaluations.
    example: if(I1<=0, 0, log(I1)) will raise an error if a voxel value is lower or equal to 0 since the log expression will be evaluated before the if statement.

    See Also:
    SoDataMeasurePredefined, SoLabelAnalysisQuantification, SoFilterAnalysisQuantification, SoGlobalAnalysisQuantification, SoFilterByMeasureProcessing, SoSieveLabelingProcessing, SoAdaptiveThresholdingProcessing

    • Field Detail

      • measureName

        public final SoSFString measureName
        Measure name that can be used in custom measure combination formula.

      • formula

        public final SoSFString formula
        Formula describing the custom measure.

    • Constructor Detail

      • SoDataMeasureCustom

        public SoDataMeasureCustom()
        Default constructor.