floor

operator

Library: Floating point number support (OMFLOAT)
Import : omfloat.xmd
Library: Binary coded decimal (BCD) numbers (OMBCD)
Import : ombcd.xmd

Returns: If the value is greater than zero, it is truncated to the specified precision. If the value is less than zero, it is rounded down to the nearest multiple of the specified precision.

Declaration

export overloaded external float function
  floor    value float x
        by value float base optional

export overloaded external bcd function
  floor    value bcd x
        by value bcd base optional

Purpose

Use floor to round down:

a floating point number
a BCD number
an integer (coerced into either a floating point or a BCD number)

If you include the keyword "by" and specify the precision, floor will round down to the multiple of the precision you have specified.

If you do not include the keyword "by" and do not specify the precision, floor will round down to the next integer whose value is less than the expression.

For values greater than zero, floor works like truncate. For values less than zero, floor rounds down to the next whole number less than or equal to the original value.

Import either ombcd.xmd or omfloat.xmd in your program after deciding whether you want BCD mathematics (excellent for financial calculations) or floating point mathematics (excellent for extremely large numbers).

BCD Example:

Calculate the area of a circle:

  import "ombcd.xmd" unprefixed
  process
      local bcd pi  initial {"3.14179"}
      local bcd radius  initial {"74"}
      local bcd area
  
      set area to floor (pi * radius * radius)
      output "area of circle with radius " || "d" % radius || " is at least " || "d" % area || "%n"

You can specify the precision of the truncation/rounding. The following program uses a precision of 0.01 to truncate/round the value at the whole cents position:

  import "ombcd.xmd" unprefixed
  process
      local bcd exchange-rate initial {1.4356}
      local bcd us-price  initial {129.95}
      local bcd canadian-price
  
      set canadian-price to floor (us-price*exchange-rate) by bcd 0.01
      output "US " || "<$,NNZ.ZZ>" % us-price || " is at least " || "<$,NNZ.ZZ>" % canadian-price || " CDN %n"

The precision specifier must be a power of 10.

Floating Point Example:

Calculate the area of a circle:

  
  import "omfloat.xmd" unprefixed
  process
      local float radius initial {"74"}
      local float area
  
      set area to floor (pi * radius * radius)
      output "Area of circle with radius " || "d" % radius || " = " || "d" % area || "%n"

Related Topics

Other Library Functions