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Round Down function

Available with Image Analyst license.

Available with Spatial Analyst license.

Overview

Returns the next lower integer, as a floating point value, for each pixel in a raster.

Round Down illustration

Notes

Input values can be positive or negative.

The output raster is always a floating-point type, regardless of the input value type.

If the input number has any values to the right of the decimal point, the output will be assigned the next lower integer value but will be represented as a floating-point number with no decimal portion. The following are examples:

    Input   Output
     5.3     5.0
     4.9     4.0
     3.0     3.0
     6.5     6.0
    -0.2    -1.0
    -2.8    -3.0

There is a difference between the Int function and the Round Down function. For example, given the following two values, Int always truncates the number:

  • 1.5 becomes 1
  • -1.5 becomes -1
while for the same two values, Round Down returns the following:
  • 1.5 becomes 1.0
  • -1.5 becomes -2.0.

Another difference is that Round Down outputs floating-point values, while Int only outputs integer values.

Parameters

Parameter nameDescription

Raster

The input values to be rounded down.

Extent Type

Choose which extent should be used in the output raster:

  • First Of—Use the extent of the first input raster to determine the processing extent.

  • Intersection Of—Use the extent of the overlapping pixels to determine the processing extent. This is the default.
  • Union Of—Use the extent of all the rasters to determine the processing extent.
  • Last Of—Use the extent of the last input raster to determine the processing extent.

Cellsize Type

Choose which cell size to use in the output raster. If all the input cell sizes are the same, all the options will yield the same results.

  • First Of—Use the first cell size of the input rasters.
  • Min Of—Use the smallest cell size of all the input rasters.
  • Max Of—Use the largest cell size of all the input rasters. This is the default.
  • Mean Of—Use the mean cell size of all the input rasters.
  • Last Of—Use the last cell size of the input rasters.


In this topic
  1. Overview
  2. Notes
  3. Parameters