Page - 2 - in Programming for Computations – Python - A Gentle Introduction to Numerical Simulations with Python 3.6, Volume Second Edition

2 1 TheFirstFewSteps Nevertheless, programs often make us frustrated when they cannot do what we wish. One typical situation might be the following. Say you have some measurementsfromadevice,and thedataare stored inafilewithaspecific format. You may want to analyze these data in Excel and make some graphics out of it. However, assume there is no menu in Excel that allows you to import data in this specific format. Excel can work with many different data formats, but not this one. Youstart searchingforalternatives toExcel that cando thesameand read this type of data files. Maybe you cannot find any ready-made program directly applicable. You have reached the point where knowing how to write programs on your own wouldbe of great help to you!With some programmingskills, you may write your own little program which can translate one data format to another. With that little piece of tailored code, your data may be read and analyzed, perhaps in Excel, or perhaps by a new program tailored to the computations that the measurement data demand. Programming The real power of computers can only be utilized if you can program them, i.e., write the programs yourself. With programming, you can tell thecomputerwhatyouwant it todo,which isgreat, since it freesyoufrompossible limitations thatcomewithprogramswrittenbyothers!Thus,with thisskill,youget an important extra option for problem solving that goes beyond what ready-made programsoffer. A program that you write, will be a set of instructions that you store in a file. These instructionsmust bewritten (accordingto certain rules) ina veryspecialized language that has adopted words and expressions from English. Such languages are known as programming (or computer) languages. When you have written your instructions (your program), you may ask the programming language to read your program and carry out the instructions. The programming language will then (if therearenoerrors) translate themeaningofyourinstructionsintorealactionsinside thecomputer. Towriteaprogramthatsolvesacomputingproblem,youneedtohaveathorough understandingof the givenproblem.That understandingmay have to be developed along the way and will obviously guide the way you write your solution program. Typically,youneed to write, test and re-write yourprogramseveral timesuntil you get it right.Thus,whatstartsoutwithacomputingproblemandendswithasensible computerprogramforitssolution, isaprocess thatmaytakesometime.Bytheterm programming,wewill mean thewholeof thisprocess. Thepurposeof thisbookis to teachyouhowtodevelopcomputerprogramsded- icated to solve mathematical and engineering problems by fundamental numerical methods. Programming Languages There are numerous computer languages for different purposes. Within the engineering area, the most widely used ones are Python, MATLAB, Octave, Fortran, C, C++, and to some extent, Maple and Mathematica. The rules for how to write the instructions (i.e. the syntax) differ between the languages.Letususean analogy. Assume you are an international kind of person, having friends abroad in England, Russia and China. They want to try your favorite cake. What can you