Representing complex numbers/Statistical analysis by PDL

Complex numbers are represented using the i function, which represents the imaginary unit that becomes available when you read PDL::Complex .

For example, to represent the complex number 3 + 2i :

use PDL;
use PDL::Complex;

my $num = 3 + 2 * i;

When this complex number is output, it will be displayed as follows.

3 + 2i

PDL can handle imaginary numbers. To handle imaginary numbers, load PDL::PDL::Complex .

use PDL::Complex;

Then the i function that represents the imaginary unit is imported.

When the imaginary unit is output, it is output as follows.

0 + 1i

The imaginary unit i was a number that squared to -1. Let's square it.

my $ret = i * i;

When this is output, it will be displayed as follows.

-1 + 0i

Perform four arithmetic operations on complex numbers using + , -, * , / as in normal operations. I can.

use PDL;
use PDL::Complex;

my $num1 = 1 + 2 * i;
my $num2 = 3 + 4 * i;

# 4 + 6i
my $sum = $num1 + $num2;

# 2 + 2i
my $sub = $num2- $num1;

# -5 + 10i
my $multi = $num1 * $num2;

# 0.44 + 0.08i
my $div = $num1/$num2;

Use the Croots function to calculate the nth root.

use PDL;
use PDL::Complex;

# 5 cube root
my $nums = Croots (5, 3);

The output of the calculation result is as follows.

[1.85398 + 0.496773i -1.35721 + 1.35721i -0.496773 -1.85398i]

Use the r2C function to convert a real number to a complex number.

use PDL;
use PDL::Complex;

my $num = r2C 5;

The output result is as follows.

5 + 0i

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