Computation Window

Data is added to the Computation Window by pressing the "Computation with Selected" button in the Database Directory window.

The computation window allows for you to state an algebraic equation to be solved with variables representing data. For example, an isotopic mixture can be generated with "0.98 * a + 0.02 * b". Or some cross sections can be weight averaged (e.g. "(2 * a + 5 * b ) / 7"). Or a simple numerical calculation can be written (e.g. "2^3 + 5.1E2 / 66").

You may store a calculation as a new variable by pressing the "Store" button. This is handy if you wish to define a material as a cross section like natural iron from its isotopes. Computation sessions may be saved and loaded with the menu at the top of the window. The current session format is not guaranteed to always be supported since it is in a beta stage of testing.

In the follow, d0 is a scalar (0-dimensional data, i.e. a number) and d2 is 2 column data (2-dimensional data, e.g., cross-section vs energy). A string is test surrounded b double quotes. For d2 data the first column is called the x values and the second column is called the y values. Also, the expression

• thicken( d2, dx [, Log] ) -> d2
  • dx => d0
  • Log => d0

is read as, the function thicken has 2 required and 1 optional argument, and returns a d2 object. The first argument must be a d2 object, the second must be a d0 object and the third, if present, must be a d0 object.

The supported operations are

* Operants must be d0 or d2

• exp( d0 ) -> d0 | exp( d2 ) -> d2
  • For exp( d2 ) only the y values are exponentiated.
• log( d0 ) -> d0 | log( d2 ) -> d2
  • For log( d2 ) only the y values are log-ed.
• log10( d0 ) -> d0 | log10( d2 ) -> d2
  • For log10( d2 ) only the y values are log10-ed.
• max( d2 ) -> d0
  • Returns the maximum y value of d2
• min( d2 ) -> d0
  • Returns of minimum y value of d2
• normalize( d2 ) -> d2
  • Returns its argument scaled so that the integral y(x) dx is 1 (i.e. normalized).
• sqrt( d0 ) -> d0 | sqrt( d2 ) -> d2
  • For sqrt( d2 ) only the y values are square rooted.
• clip( d2, yMin, yMax ) -> d2
  • yMin -> d0
  • yMax -> d0
  • Returns a d2 object whose data is the same as the first arguments, except that y values are clip at yMin and yMax.
• convolution( d2, d2 [, dxMax] ) -> d2
  • Returns the convolution, c(x) = integral f(x') * g(x-x'), of the first two arguments, f(x) and g(x) respectively, to this function. The maximum spacing of the output x-values can be set using dxMax. If dxMax is not set, then it is set to xDomain / 20 where xDomain is the smallest x domain of f and g. Be careful not to have to dxMax be to small or the calculation will take a long time. The x domain of the output only includes the regions where the smaller x domain completely overlaps the larger x domain.
• flattop( xMin, xMax ) -> d2
  • xMin = d0
  • xMax = d0
  • Creates a d2 object with points ( ( xMin, 1 ), ( xMax, 1 ) ).
• gauss( xCenter, xWidth [, f [, xsigma [, xMin [, xMax ] ] ] ] ) -> d2
  • xCenter -> d0
  • xWidth -> d0
  • f -> d0
• xsigma -> d0
• xMin -> d0
• xMax -> d0
• Returns a d2 object that is a Gaussian centered at xCenter with width xWidth. The interpolation accuracy of the Gaussian is determine by f (default = 1e-3 or 0.1%). The x range of the returned object is between xMin and xMax. The x range is also limits by abs( x - xCenter ) <= xsigma * xWidth.
• pow( d0, d0 ) -> d0 | pow( d2, d0 ) -> d2 | pow( d0, d2 ) -> d2
  • pow( a, b ) is a^b.
• ramp( xMin, xMax [, Down ] ) -> d2
  • xMin = d0
  • xMax = d0
  • Down = d0
  • Creates a d2 object with points ( ( xMin, 0 ), ( xMax, 1 ) ) if Down = 0 (default) or with points ( ( xMin, 1 ), ( xMax, 0 ) ) if Down != 0.
• range( d2, xMin, xMax ) -> d2
  • xMin = d0
  • xMax = d0
  • Returns a d2 object that consist of all points in the first argument that lie between xMin and xMax.
• rangex( d2, xMin, xMax ) -> d2
  • xMin = d0
  • xMax = d0
  • Returns a d2 object that consist of all points in the first argument that lie between xMin and xMax, with the points xMin and xMax added if not in the first argument.
• scalex( d2, operation, unit) -> d2
  • operation -> string
  • unit -> string
  • Returns a d2 object that has been modified by the operation and has a new set of units.
  • Examples
    • scalex( a, "sin(x)", "")
    • scalex( b, "x * 1E-24", "cm^2")
• thicken( d2, dx [, Log] ) -> d2
  • dx -> d0
  • Log -> d0
  • Increase the density of x points in d2 so the the x spacing is no greater than dx for Log = 0 (the default). If Log != 0, dx is factional increase of x value spacing (e.g. x_n / x_(n-1)). For Log = 0, dx must be greater than 0, else dx must be greater than 1.
• triangle( xMin, xMid, xMax ) -> d2
  • xMin = d0
  • xMid = d0
  • xMax = d0
  • Creates a d2 object with points ( ( xMin, 0 ), ( xMid, 1 ), ( xMax, 0 ) ).

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