Table of Contents

## How do you write complex numbers in Fortran?

Complex numbers in Fortran are stored in rectangular coordinates as a pair of real numbers (real part first, followed by the imaginary part). The default kind of complex numbers is always the same as the default kind of the real data type. So a complex variable of kind 4 will contain two reals of kind 4.

### How do you define a complex variable in Fortran?

Fortran allows variables to be declared as complex numbers. Variables such as this are declared with their first value as the real component and the second as the imaginary. The following statements show an example of a complex variable declaration in a portion of a program.

#### What are the different types of functions used in Fortran 90 95?

Procedures. Fortran has 2 types of procedures: functions, which return a value (and usually should not modify their arguments), and subroutines, which presumably modify their arguments or have other side effects.

**How do I transpose in Fortran?**

TRANSPOSE Function

- Description. The TRANSPOSE function transposes an array of rank two. Syntax. TRANSPOSE (matrix)
- Arguments. matrix is an INTENT(IN) rank two array of any type.
- Result. The result is of rank two and the same type and kind as matrix. Its shape is (n, m), where (m, n) is the shape of matrix.

**What is complex data type in Fortran?**

The complex data type, COMPLEX , which defaults to a synonym for COMPLEX*8 , is a pair of REAL*4 values that represent a complex number. The first element represents the real part and the second represents the imaginary part. The default size for a COMPLEX item (no size specified) is 8 bytes.

## What should a Fortran variable name start with?

The rules are: A variable name must start with an letter. After that, the rest of the name can contain only letters (a–z), digits (0–9) or underscore character _ (no blanks!). A variable name can be no longer than 31 characters.

### What is temp in Fortran?

Define directory for temporary files. SPARC: 77/90 x86:77. Set directory for temporary files used by the compiler to be dir . No space is allowed within this option string.

#### What does C do in Fortran?

When a Fortran routine calls a C function: If the called C function returns a value, call it from Fortran as a function. If the called C function does not return a value, call it as a subroutine.

**How do you reshape in Fortran?**

It constructs an array with a specified shape shape starting from the elements in a given array source. If pad is not included then the size of source has to be at least product (shape). If pad is included, it has to have the same type as source.

**Which of the following are data types in Fortran 90?**

SPARC: Fortran 90 and C Data Types

Fortran 90 Data Type | C Data Type | |
---|---|---|

REAL (KIND=4) x REAL (KIND=8) x REAL (KIND=16) x | float x ; double x ; long double x ; | |

INTEGER x | int x ; | |

INTEGER (KIND=1) x INTEGER (KIND=2) x INTEGER (KIND=4) x INTEGER (KIND=8) x | signed char x ; short x ; int x ; long long int x; | |

LOGICAL x | int x ; |

## How do I declare a variable in Fortran?

Variable names in Fortran consist of 1-6 characters chosen from the letters a-z and the digits 0-9. The first character must be a letter. Fortran 77 does not distinguish between upper and lower case, in fact, it assumes all input is upper case. However, nearly all Fortran 77 compilers will accept lower case.