Get Real Part from a Complex Number in Haskell

In Haskell, we can use realPart function and pattern matching to get the real part from a complex number. In the first example we are going to use (realPart c) function and in the second example, we are going to use patter matching as (x:+_) = c.

Algorithm

• Step 1 ? The Data.Complex module is imported to work over the complex numbers.

• Step 2 ? Program execution will be started from main function. The main() function has whole control of the program. It is written as main = do.

• Step 3 ? The variable named, "c" is being initialized. It will hold the complex number value whose real part is to be printed.

• Step 4 ? The resultant real part is printed to the console on calling the realPart function.

Example 1

In this example, we are going to see that how we can print the real part of the complex number. This can be done by using realPart function.

import Data.Complex

main :: IO ()
main = do
   let c = 3 :+ 4
   print (realPart c)

Output

3

Example 2

In this example, the complex number c is matched against the pattern (x:+_), where x is the real part and _ is a placeholder for the imaginary part. This extracts the real part of the complex number and assigns it to x.

import Data.Complex

main :: IO ()
main = do
   let c = 3 :+ 4
   let (x:+_) = c
   print x

Output

3

Conclusion

The real part of a complex number is the coefficient of the real component in its standard form of representation, a + bi, where a and b are real numbers, and i is the imaginary unit. In Haskell, a real part of the Complex number can be fetched, by using realPart function, or by using pattern matching.