Interpolation
The various techniques of interpolation see their widest application in the field of engineering. Here are a few examples of real scenarios where interpolation is truly a godsend.
Telecommunication
✏ When an analog signal (such as what you speak on the phone) is transmitted over a long distance, it needs to be converted to a digital format.
✏ Digital data is discrete rather than continuous, and hence, the signal needs to be sampled at regular intervals.
✏ The sampled function is optimized and sent across the world through physical cables or wires.
✏ At the recipient end, once the sampled version of the signal is obtained, the original signal, obviously, needs to be reconstructed.
✏ How does one obtain the entire original signal from the bits and pieces that have been transmitted? Answer: Interpolation.
Airplane, or Aerospace Engineering
✏ For a rocket that is sent into outer space, the value of each of its parameters, like speed, acceleration, temperature, and so on, can be represented in the form of mathematical functions. Readings of these values are taken at regular intervals.
✏ In case of any unforeseen event, for example: To avert a bigger crisis of shrapnel from some explosion in space whizzing about in the rocket's trajectory, scientists would need to have access to the values of each parameter at various specific instants of time.
✏ To obtain the values for those instants where readings were not explicitly taken, interpolation can be used.
Thermodynamics and Fluid Mechanics
✏ In various industries pertaining to chemicals, mechanical engineering, or material sciences, knowing the thermal and physical properties of various fluid substances is a must.
✏ Although the calculation and computation of many of these values is done with the help of software and databases, on a very high scale, the sheer volume of numbers to be crunched makes it a tedious, time-consuming process.
✏ The techniques of interpolation eradicate the tedious task of calculating many values physically which in turn saves a LOT of time.
Extrapolation
Extrapolation and prediction go hand in hand, and hence, in almost every industry whenever anything needs to be planned for the future, or with reference to projected values, extrapolation is always used.
Forecasting
Here are a few real examples where extrapolation is used to forecast future trends.
1. It is possible to predict what the population of the world will be in any future year by extrapolating the data from the past few decades that we currently have.
2. Physical data about our planet, solar system, and in fact, the entire universe can be extrapolated to predict major events including catastrophes and natural disasters. A simple example would be: studying the temperature, width, depth, and other parameters of a fault line with respect to time, and extrapolating the data to predict when an earthquake could occur.
3. Virologists can extrapolate the data regarding the outbreak of a disease in a particular area, and predict the extent to which it will spread over a period of time. This extrapolated data can prove to be invaluable while designing strategies to contain the disease.
4. Corporate firms use extrapolation on almost a daily basis to predict growth, profit, and other similar trends. In fact, they design their business strategies for the entire year on the basis of this extrapolated data.
5. Another statistical application of extrapolation methods is the prediction of stock market trends. However, this is not recommended at all, as the extrapolated data sometimes may not match the actual situation, and can end up misleading anyone who makes decisions on its basis.
Engineering and Mathematical Applications.
1. When audio signals are transmitted over long distances, they are susceptible to disturbance and noise. Using extrapolation techniques to predict the signal during its reconstruction, at the recipient end, can help obtain a much clearer signal.
2. The field of image processing has benefited greatly because of extrapolation. As a result of nonlinear extrapolation of data, HDTVs have the simplicity of computation.