The Endocrine System Essentials. 1  The endocrine system is made up of a network of glands. 2  These glands secrete hormones to regulate many bodily functions, including growth and metabolism. 3  Endocrine diseases are common and usually occur when glands produce an incorrect amount of hormones.
The Fourier transform is called the frequency domain representation of the original signal. The term Fourier transform refers to both the frequency domain representation and the mathematical operation that associates the frequency domain representation to a function of time.
Nearly always, the function that is used to transform the data is invertible, and generally is continuous. The transformation is usually applied to a collection of comparable measurements. For example, if we are working with data on peoples' incomes in some currency unit, it would be common to transform each person's income value by the logarithm function.