SP_AMSUM

AMSUM()

  Short:
  ------
  AMSUM() Sum on a given element of multi-dim array

  Returns:
  --------
  <nSum> => sum of array element

  Syntax:
  -------
  AMSUM(aMult,nElem,[bCondition])

  Description:
  ------------
  Returns sum of array <aMult> element <nElem>.

  [bCondition] is an optional codeblock used to select
  a subset of the  array. This could be used to filter out 0's or
  non-numeric elements.  The block must accept a subarray as a
  parameter, and return  true or false <expL> to determine if this
  element is part of the desired subset. Please note that the
  codeblock accepts the whole subarray, not  just subarray element
  <nElem>

  Examples:
  ---------

   ?"Total file size here is "
   ??AMSUM(DIRECTORY(),2)

   ?"Total .EXE file size here is "
   ??AMSUM(DIRECTORY(),2,{|e|".EXE"$e[1]}  )

   use customer
   ?"Total field size "
   ??AMSUM(DBSTRUCT(),3)

   use customer
   ?"Total CHARACTER field size "
   ??AMSUM(DBSTRUCT(),3,{|e|e[2]=="C"} )

  Notes:
  -------
  Coded by Matthew Maier.

  Presumes all sub-arrays are of equal length

  Source:
  -------
  S_AMSTAT.PRG

 

SP_AMSTDDEV

AMSTDDEV()

  Short:
  ------
  AMSTDDEV() Standard Deviation on a given element of
  multi-dim array

  Returns:
  --------
  <nVariance> => average of array element

  Syntax:
  -------
  AMSTDDEV(aMult,nElem,[bCondition])

  Description:
  ------------
  Returns Standard Deviation of array <aMult> element
  <nElem>.  [bCondition] is an optional codeblock used to select a
  subset of the array. This could be used to filter out 0's or
  non-numeric elements.

  The block must accept a subarray as a parameter, and
  return true or false <expL> to determine if this element is
  part of the desired subset. Please note that the codeblock
  accepts the whole subarray, not  just subarray element <nElem>

  Examples:
  ---------
   ?"Total file size here is "
   ??AMSUM(DIRECTORY(),2)

   ?"Total .EXE file size here is "
   ??AMSUM(DIRECTORY(),2,{|e|".EXE"$e[1]}  )

   ?"Standard Deviation:"
   ??AMSTDDEV(DIRECTORY(),2,{|e|".EXE"$e[1]}  )

  Notes:
  -------
  Coded by Matthew Maier.

  Presumes all sub-arrays are of equal length

  Source:
  -------
  S_AMSTAT.PRG

 

SP_AMAVERAGE

AMAVERAGE()

  Short:
  ------
  AMAVERAGE() Average on a given element of multi-dim array

  Returns:
  --------
  <nAverage> => average of array element

  Syntax:
  -------
  AMAVERAGE(aMult,nElem,[bCondition])

  Description:
  ------------
  Returns average of array <aMult> element <nElem>.

  [bCondition] is an optional codeblock used to select
  a subset of the  array. This could be used to filter out 0's or
  non-numeric elements.  The block must accept a subarray as a
  parameter, and return  true or false <expL> to determine if this
  element is part of the desired  subset.

  Please not that the codeblock accepts the whole
  subarray, not  just subarray element <nElem>

  Examples:
  ---------

   ?"Average file size here is "
   ??amaverage(DIRECTORY(),2)

   ?"Average .EXE file size here is "
   ??amaverage(DIRECTORY(),2,{|e|".EXE"$e[1]}  )

   use customer
   ?"Average field size "
   ??amaverage(DBSTRUCT(),3)

  Notes:
  -------
  Presumes all sub-arrays are of equal length

  Coded by Matthew Maier.

  Source:
  -------
  S_AMSTAT.PRG

 

Array Terms

Array :

A data structure that contains an ordered series of values called elements. The elements of an array are referred to by ordinal number; the first element is number 1, the second is number 2, etc. A numeric expression used to specify an element of an array is referred to as a subscript or index. In Clipper language, the elements of an array may be values of any type, including references to other arrays.

See Also : Array Reference, Nested Array, Subarray, Subscript

Array Functions :

Those functions that specifically perform their tasks on arrays.

See Also : Array, Element, Function, Subscript

Array Iterator :

A function that traverses an array, performing an operation on each element.

See Also : Array

Array Reference :

A special data value that allows access to an array. In Clipper language, program variables and array elements cannot directly contain arrays; they may, however, contain array references. A variable that contains a reference to a particular array is said to refer to that array, and the array’s elements may be accessed by applying a subscript to the variable. If the value of a variable containing an array reference is assigned to a second variable, the second variable will contain a copy of the array reference; both variables then refer to the same array, and the array’s elements may be accessed by applying a subscript to either variable.

See Also: Array, Nested Array, Subarray, Subscript

Constant Array :

See : Literal Array

Dimension :

The maximum number of subscripts required to specify an array element. For example, a two-dimensional array must have two subscripts, a three-dimensional array must have three subscripts and so on.

See Also: Subscript

Element :

A component unit of an array, usually referred to by a numeric subscript or index.

See Also: Array, Subscript

Literal Array :

In Clipper language, an array specified by enclosing a series of expressions in curly ({}) braces. A literal array is an expression that evaluates to an array reference.

See Also: Array, Array Reference

Multidimensional Array :

In Clipper language, an array whose elements consist entirely of references to other arrays (called subarrays). The elements of the subarrays may, in turn, contain references to other arrays. Arrays organized in this fashion are said to be nested. Each level of nesting may be viewed as a dimension of the main array, and the elements of the subarrays may be accessed by applying multiple subscripts to the main array.

See Also: Array, Array Reference, Nested Array, Subscript

Nested Array :

In Clipper language, two arrays are said to be nested if one of them contains a reference to the other. When an array contains a reference to a second array, the second array is sometimes called a subarray of the first array

See Also: Array, Array Reference, Multidimensional Array

Reference :

A special value that refers indirectly to a variable or array. If one variable contains a reference to a second variable (achieved by passing the second variable by reference in a function or procedure call), operations on the first variable (including assignment) are passed through to the second variable. If a variable contains a reference to an array, the elements of the array can be accessed by applying a subscript to the variable.

See Also: Array Reference, Parameter

Single-dimensional Array :

In Clipper language, an array whose elements do not contain references to other arrays.

See Also:Array, Multidimensional Array, Nested Array, Subarray, Subscript

Sort Order :

Describes the various ways database files and arrays are ordered.

. Ascending

Causes the order of data in a sort to be from lowest value to highest value.

. Descending

Causes the order of data in a sort to be from highest value to lowest value.

. Chronological

Causes data in a sort to be ordered based on a date value, from earliest to most recent.

. ASCII

Causes data in a sort to be ordered according to the ASCII Code values of the data to be sorted.

. Dictionary

The data in a sort is ordered in the way it would appear if the items sorted were entries in a dictionary of the English language.

. Collating Sequence

Data in a sort will be placed in sequence following the order of characters in the Extended Character Set.

. Natural

The order in which data was entered into the database.

Subarray :

In Clipper language, an array that is referred to by an element of another array.

See Also:Array, Multidimensional Array, Nested Array, Subscript

Subscript :

A numeric value used to designate a particular element of an array. Applying a subscript to an array is called subscripting the array. In Clipper programs, subscripting is specified by enclosing a numeric expression in square   ([ ]) brackets after the name of a program variable. The variable is then said to be subscripted.

See Also: Array, Array Reference, Nested Array, Subarray

Two-dimensional Array :

An array that has two dimensions. In Clipper language, an array whose elements contain references to other arrays, all of which have the same length and do not refer to other arrays.

See Also: Array, Array Reference, Nested Array, Subscript