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

Converts a raster dataset to an ASCII file representing raster data.

Usage tips

Command line and Scripting

• The input raster dataset can be any valid raster dataset.

• The ASCII file consists of header information containing a set of keywords, followed by cell values in row-major order. The file format is

      NCOLS xxx
      NROWS xxx
      XLLCENTER xxx | XLLCORNER xxx
      YLLCENTER xxx | YLLCORNER xxx
      CELLSIZE xxx
      NODATA_VALUE xxx
      row 1
      row 2
      .
      .
      .
      row n

  where xxx is a number and the keyword NODATA_VALUE is optional and defaults to -9999.

  The Raster To ASCII tool will only generate files where the location of the raster is based off the lower left corner (LLCORNER). Note that the Raster To ASCII tool supports both LLCENTER and LLCORNER. For example:

      NCOLS 480
      NROWS 450
      XLLCORNER 378922
      YLLCORNER 4072345
      CELLSIZE 30
      NODATA_VALUE -32768
      43 2 45 7 3 56 2 5 23 65 34 6 32 54 57 34 2 2 54 6
      35 45 65 34 2 6 78 4 2 6 89 3 2 7 45 23 5 8 4 1 62 ...

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

• The end of each row of data from the raster is terminated with a carriage return in the file.

• Both integer and floating point rasters can be converted to an ASCII format.

• The output will be an ASCII text file.

• 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
RasterToASCII_conversion <in_raster> <out_ascii_file>

Parameter	Explanation	Data Type
<in_raster>	The input raster dataset. The raster can be integer or floating point.	Composite Geodataset
<out_ascii_file>	The output ASCII file.	File

Data types for geoprocessing tool parameters

Command line example

RasterToASCII_conversion d:\images\Myraster.mdb\Flemming Flemming.txt

Scripting syntax
About getting started with writing geoprocessing scripts
RasterToASCII_conversion (in_raster, out_ascii_file)

Parameter	Explanation	Data Type
in_raster (Required)	The input raster dataset. The raster can be integer or floating point.	Composite Geodataset
out_ascii_file (Required)	The output ASCII file.	File

Data types for geoprocessing tool parameters

Script example

# RasterToASCII_sample.py
# Description: 
#   Converts a raster into an ASCII file representing raster data.
# 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"
    OutAsciiFile = "C:/data/raster2ascii.asc"

    # Process: RasterToASCII_conversion
    gp.RasterToASCII_conversion(InRaster, OutAsciiFile)

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

Map Algebra syntax
See GridASCII.

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

ArcObjects syntax
See ExportToASCII.

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

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