intel fortran array assignment

• Fortran Tutorial
• Fortran - Home
• Fortran - Overview
• Fortran - Environment Setup
• Fortran - Basic Syntax
• Fortran - Data Types
• Fortran - Variables
• Fortran - Constants
• Fortran - Operators
• Fortran - Decisions
• Fortran - Loops
• Fortran - Numbers
• Fortran - Characters
• Fortran - Strings

Fortran - Arrays

• Fortran - Dynamic Arrays
• Fortran - Derived Data Types
• Fortran - Pointers
• Fortran - Basic Input Output
• Fortran - File Input Output
• Fortran - Procedures
• Fortran - Modules
• Fortran - Intrinsic Functions
• Fortran - Numeric Precision
• Fortran - Program Libraries
• Fortran - Programming Style
• Fortran - Debugging Program
• Fortran Resources
• Fortran - Quick Guide
• Fortran - Useful Resources
• Fortran - Discussion
• Selected Reading
• UPSC IAS Exams Notes
• Developer's Best Practices
• Questions and Answers
• Effective Resume Writing
• HR Interview Questions
• Computer Glossary

Arrays can store a fixed-size sequential collection of elements of the same type. An array is used to store a collection of data, but it is often more useful to think of an array as a collection of variables of the same type.

All arrays consist of contiguous memory locations. The lowest address corresponds to the first element and the highest address to the last element.

Arrays can be one- dimensional (like vectors), two-dimensional (like matrices) and Fortran allows you to create up to 7-dimensional arrays.

Declaring Arrays

Arrays are declared with the dimension attribute.

For example, to declare a one-dimensional array named number, of real numbers containing 5 elements, you write,

The individual elements of arrays are referenced by specifying their subscripts. The first element of an array has a subscript of one. The array numbers contains five real variables –numbers(1), numbers(2), numbers(3), numbers(4), and numbers(5).

To create a 5 x 5 two-dimensional array of integers named matrix, you write −

You can also declare an array with some explicit lower bound, for example −

Assigning Values

You can either assign values to individual members, like,

or, you can use a loop,

One-dimensional array elements can be directly assigned values using a short hand symbol, called array constructor, like,

please note that there are no spaces allowed between the brackets ‘( ‘and the back slash ‘/’

The following example demonstrates the concepts discussed above.

When the above code is compiled and executed, it produces the following result −

Some Array Related Terms

The following table gives some array related terms −

Passing Arrays to Procedures

You can pass an array to a procedure as an argument. The following example demonstrates the concept −

In the above example, the subroutine fillArray and printArray can only be called with arrays with dimension 5. However, to write subroutines that can be used for arrays of any size, you can rewrite it using the following technique −

Please note that the program is using the size function to get the size of the array.

Array Sections

So far we have referred to the whole array, Fortran provides an easy way to refer several elements, or a section of an array, using a single statement.

To access an array section, you need to provide the lower and the upper bound of the section, as well as a stride (increment), for all the dimensions. This notation is called a subscript triplet:

When no lower and upper bounds are mentioned, it defaults to the extents you declared, and stride value defaults to 1.

The following example demonstrates the concept −

Array Intrinsic Functions

Fortran 90/95 provides several intrinsic procedures. They can be divided into 7 categories.

Vector and matrix multiplication

Construction

Manipulation