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1990-06-26
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10. ERROR MESSAGES
Most IDRISI modules generate module-specific error messages when
responses lead to conditions that are unworkable, or when
unexpected results may be generated. The MODULE DESCRIPTIONS
section lists these at the bottom of each module description
sheet. If an error message occurs during the running of a module,
first check the specific module sheet. If the error message is
not described there, then the message has been generated by a
general set of routines (typically involved with input / output)
that all IDRISI modules share. These general error messages are
listed here, along with a discussion of the cause or solution if
it is not obvious. Entries in square brackets indicate parts of
the message that will vary depending upon the circumstance, with
the entry indicating the nature of what will appear.
10.1 Data Entry Errors
1. Please enter a number between 1 and [another number].
- either your response to a menu was not understood, or
the value you have entered is not permissible (e.g.,
you have entered a real number when an integer is
required). Enter an integer value within the range
indicated.
2. Numeric value input is incorrectly formatted or out of range.
- this message will most probably appear in instances
where an integer number is required, and a real number
was entered. However, any non-numeric entry will
generate this result when a number is required.
Similarly, entering a value greater than 32767 or less
than -32768 when an integer is required will result in
this error. Similarly, byte values must fall within
the range of positive 0 - 255.
3. Illegal character in name.
- an illegal character has been used as part of an image
name. If in doubt, use an alphabetic character for the
first letter and either alphabetic characters or numerals
for all remaining characters.
4. Image name is too long (max = 8 characters).
- Image names are restricted to 8 characters or less. In
some rare instances, this message may appear for non-
image file names. The interpretation, however, is
identical.è
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5. File extensions not allowed.
- Although IDRISI data files are stored with specific
extensions (eg., .IMG for image files), you should not
use them when referring to data sets. Thus, for example,
an image stored as SOILS.IMG would be referred to by the
simple name SOILS (without the .IMG).
6. Please enter a name up to 8 characters in length.
- You pressed return without specifying an image or
file name.
7. No on-line help. See IDRISI manual.
- A request for help was made when input of an image name
was required. See the MODULE DESCRIPTION sheet for the
module you were using -- it lists complete instructions
for that module. If you are unfamiliar with any of the
terminology, see BASIC CONCEPTS and GETTING STARTED.
10.2 Data File Access Errors
8. IDRISI documentation file for [file name] does not exist on
[drive and path name].
- a data file was found, but not its documentation file.
Use the DIR operating system command to confirm its
existence. If it appears in the directory, run ENVIRON
to be sure that the documentation file extension is the
same as that attached to the documentation file in
question. If it does not exist, run DOCUMENT to create
one.
9. IDRISI image file for [image name] does not exist on [drive
and path name].
- a documentation file was found, but not its image file.
Use the DIR operating system command to confirm its
existence. If it appears in the directory, run ENVIRON
to be sure that the image file extension listed is the
same as that attached to the image file in question.
10. Image file [file name] does not exist on [drive and path
name].
- neither the image file nor its documentation file were
found. Check that the drive and path are correctly
identified. If not, change them with the ENVIRON module.è
Otherwise, use the DIR operating system command to
confirm its existence, and check your spelling.
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11. Vector file [file name] does not exist on [drive and path
name].
- neither the vector file nor its documentation file were
found. Check that the drive and path are correctly
identified. If not, change them with the ENVIRON module.
Otherwise, use the DIR operating system command to
confirm its existence, and check your spelling.
12. Attribute values file [file name] does not exist on [drive
and path name].
- neither the attribute values file nor its documentation
file were found. Check that the drive and path are
correctly identified. If not, change them with the
ENVIRON module. Otherwise, use the DIR operating system
command to confirm its existence, and check your
spelling.
13. IDRISI vector file missing.
- The vector file indicated could not be found. Check the
spelling. Also, make sure that the vector file's
extension is the same as that indicated in the environ-
ment file.
14. IDRISI attribute values file missing.
- The attribute file indicated could not be found. Check
the spelling. Also, make sure that the values file's
extension is the same as that indicated in the environ-
ment file.
15. Access attempted to non-existent data file.
- An unspecific error message that indicates that the data
file required could not be found. This message is
unlikely to occur very often, but would most probably be
associated with trying to access a non-image file. For
example, a font file not found by DISPLAY would generate
this message.
10.3 Data File Format Errors
16. Unexpected end of file.
- more data were expected that were actually present in the
file. One possible explanation is that the documentation
file does not correctly describe the contents of the data
file it documents. Another possibility is that two
images are being overlaid when they do not match in theè
number of rows and columns each has (which they must).
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17. Attempt to read beyond end of data file.
- this message arises under a different circumstance, but
the interpretation is the same as the "Unexpected end of
file" message above.
18. The [data type] data type is not supported by this module.
- the data type specified in the documentation file is not
supported by the module you are trying to use. This is an
unlikely message unless you are sharing data files with
someone who has a later version of IDRISI than you do.
19. The [data type] vector data type is not supported by this
module.
- data type in vector files refers to the identifiers (and
not the coordinate values which are always interpreted as
real numbers). IDRISI recognizes that the identifiers
can only be of type integer or real.
20. The [file type] file type is not supported for vector files.
- only ASCII and simple binary files are supported for
vector data.
21. Classified values file must contain integer class data.
- the documentation file indicates that the number of
classes is greater than zero (and thus that it is
classified), but that the file contains real numbers
-- an impossibility. If the data are raw unclassified
data, be sure that the number of classes is stated as
zero (an indication that the data are raw values).
22. Only integer attribute values files may contain a legend.
- the documentation file indicates that a legend is
attached, but the data type is listed as real or string.
Only integer values files can contain a legend
(logically).
10.4 Disk and Directory Errors
23. Insufficient disk space for attempted operation.
- your data disk is full!
24. Insufficient disk space for block transfer.
- although the cause is slightly different, the meaning is
identical to the one above -- your disk is full!è
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25. Data disk directory is full.
- the directory track of your data disk has no more room
for file names.
26. File disappeared. Has the data disk been removed?
- Have you have removed a disk while it was still being
used? This error message also tends to occur when there
is an internal problem in a module's file record keeping.
If you get this happening consistently, please notify
the IDRISI bulletin-board system.
10.5 Data Processing Errors
27. Floating point overflow (number too large)
- it is possible (although unlikely) that an operation may
result in the generation of a number that is beyond your
computer's range.
28. Division by zero attempted.
- this is unlikely to occur, but a division by zero leads
to an infinite result -- an impossible operation!
29. Square root of negative number attempted.
30. Logarithm of zero or negative number attempted.
31. Attempt to convert out-of-range real to integer.
- integers must fall within a range of -32768 to +32767. An
attempt has been made to convert a real number outside
this range into an integer.
32. Out of range value assigned to scalar.
- a value was expected to be either a byte value or an
integer and the value did not conform to the expected
range. Byte values must be positive within the range of
0 - 255. Integers may be positive or negative within the
range of -32768 to +32767.
10.6 System Errors
33. IDRISI environment file missing.
- The file named IDRISI.ENV could not be found on the
default drive. Check that your default drive (the oneè
indicated by the operating system prompt) correctly
indicates the drive that contains the IDRISI program
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modules and the environment file. If the environment
file is missing, copy it onto the disk with the IDRISI
program modules, and run ENVIRON to confirm that it is
correctly configured.
34. The printer code file named IDRISI.PRN could not be found.
- the module you are using accesses a printer and the
printer code file (IDRISI.PRN) could not be found.
Review the INSTALLATION steps required to install a
proper code file and redo that portion of the
installation procedure again.
35. Structural error exists in the printer code file named
IDRISI.PRN
- review the INSTALLATION section on the creation of a
printer code file. The code file you are using has an
error in its structure.
In addition to the error messages listed above, there are two
messages that are unlikely to occur due to your own actions.
These are unspecified system errors that may signal a problem
in the program code. If one of these should occur, and if the
solution is not obvious, please notify the IDRISI bulletin-
board system. You will notice that each records an error
number and sometimes an "offset" (an indication of where the
error occurred within the program). When reporting an error,
indicate its type, the error number and the offset.
36. IDRISI input/output system error [error number] [offset = ?]
- a system error associated with input or output to the
disk, keyboard, printer or screen. Check also that
the environment file correctly records the proper disk
drive and data path.
37. IDRISI runtime system error [error number] [offset = ?]
- a system error associated with some aspect of data
processing.
è
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