Raster to Float (Conversion)
Release 9.2 Last modified April 2, 2008	Print all topics in : "Tools"

Converts a raster dataset to a file of binary floating-point values representing raster data.

Usage tips

Command line and Scripting

• The input can be any valid raster dataset.

• Two outputs are created: an IEEE floating-point format 32-bit signed binary file with a .flt extension and an ASCII header file named with a .hdr extension. Both will use the same output floating-point raster file name.

• The ASCII file consists of header information containing a set of keywords. The file format is

      NCOLS xxx
      NROWS xxx
      XLLCENTER xxx | XLLCORNER xxx
      YLLCENTER xxx | YLLCORNER xxx
      CELLSIZE xxx
      NODATA_VALUE xxx
      BYTEORDER <MSBFIRST | LSBFIRST>

  where xxx is a number and the keyword NODATA_VALUE is always written as -9999.

  The BYTEORDER represents how multibyte binary numbers are stored on the system on which the binary file was generated. On Intel-based systems, the byte order is MSBFIRST (also known as Big Endian). On most other architectures (Macintosh and all UNIX systems except Alpha), the byte order is LSBFIRST (also known as Little Endian).
  
  

• The NODATA_VALUE is the value in the output file assigned to those cells in the input raster that contain NoData. This value is normally reserved for those cells whose true value is unknown.

• By default, NoData values on the input raster will have a value of -9999 in the output float file. If you want to use another value to represent NoData, a procedure similar to the following can be applied:

  • Run the Spatial Analyst IsNull function on the original raster. The output will be a raster of binary values, where 1 corresponds to NoData on the original raster and 0 is any other value.
  • Run the Spatial Analyst Con function, specifying the IsNull result as the Input Conditional Raster, the new value to assign NoData values to as the Input True value, the original raster as the Input False raster, and a condition Expression of "value = 1".
  • Convert the Con output raster to a floating-point binary file with Raster To Float.
  • Change the value of NODATA_VALUE in the ASCII header file to the value that NoData was converted to.

• This tool only writes the origin as LLCORNER. The Float To Raster tool will support LLCENTER in addition to LLCORNER.

• The following environments affect this tool: current workspace, scratch workspace, output coordinate system, and output extent.

Command line syntax
An overview of the Command Line window
RasterToFloat_conversion <in_raster> <out_float_file>

Parameter	Explanation	Data Type
<in_raster>	The input raster dataset. The raster can be integer or floating point.	Composite Geodataset
<out_float_file>	The output floating-point raster file. The file name must have a .flt extension.	File

Data types for geoprocessing tool parameters

Command line example

RasterToFloat c:\data\images.mdb\landuse.tif c:\data\landuse.flt

Scripting syntax
About getting started with writing geoprocessing scripts
RasterToFloat_conversion (in_raster, out_float_file)

Parameter	Explanation	Data Type
in_raster (Required)	The input raster dataset. The raster can be integer or floating point.	Composite Geodataset
out_float_file (Required)	The output floating-point raster file. The file name must have a .flt extension.	File

Data types for geoprocessing tool parameters

Script example

# RasterToFloat_sample.py
# Description: 
#   Converts a raster into a file of binary floating point.
# Requirements: None
# Author: ESRI
# Date: Oct 20, 2005
# Import system modules
import arcgisscripting

# Create the Geoprocessor object
gp = arcgisscripting.create()

try:
    # Set local variables
    InRaster = "C:/data/raster1"
    OutFloatFile = "C:/data/raster2float.flt"

    # Process: RasterToFloat_conversion
    gp.RasterToFloat_conversion(InRaster, OutFloatFile)

except:
    # Print error message if an error occurs
    print gp.GetMessages()

Map Algebra syntax
See GridFloat.

The Spatial Analyst extension must be present to use this link.

ArcObjects syntax
See ExportToFloat.

The Spatial Analyst extension must be present to use this link.

Please visit the Feedback page to comment or give suggestions on ArcGIS Desktop Help.
Copyright © Environmental Systems Research Institute, Inc.