Skip to content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Error Dictionary

Introduction

ISIS categorizes errors into four different types to indicate their sources.

Unknown Error

This error category encompasses errors that fall outside the scope of User, Programmer, or I/O Errors as listed below. It's typically the most common error and is displayed as a generic error.

Example:

**ERROR** Unable to find PVL group [SearchChip].

User Error

This error occurs when users select invalid values for input parameters. Examples include entering a negative integer for a parameter that only allows positive integers, mistyping parameters, or inputting a value not in a required list (such as 8-bit, 16-bit, or 32-bit). Typically, this error is associated with user input provided either in the ISIS graphical user interface (GUI) or via the command line.

Example:

**USER ERROR** Unknown parameter [to].

Programmer Error

This particular error is uncommon, arising when the programmer provides invalid information to a C++ class and/or method. Typically, these errors are detected by the programmer during the software development phase. They might occur in exceptional situations like array out-of-bounds or memory leaks. Users encountering these errors should open an issue in the ISIS Repository.

Example:

**PROGRAMMER ERROR** Cannot compare a invalid angles with the < operator.

I/O Error

File I/O errors encompass operations such as opening, closing, reading, or writing files. These errors may involve: 1) attempting to access a non-existent file upon opening or allocation, often due to misspellings or incorrect directory paths, 2) encountering read and/or write permission issues stemming from user or group ownership, and 3) facing inadequate disk space for allocating an output file. However, these errors do not pertain to cases where a file lacks the expected values inside it, such as reading a corrupted PVL.

Example:

**I/O ERROR** Unable to open [test.cub].