Seite - 56 - in Programming for Computations – Python - A Gentle Introduction to Numerical Simulations with Python 3.6, Band Second Edition

56 2 AFewMoreSteps One more handyfunction fromnumpydeservesmention. If you have an array15 with numbers, you can shuffle those numbers in a randomized way with the shuffle function, In [1]: import numpy as np In [2]: a = np.array([1, 2, 3, 4]) In [3]: np.random.shuffle(a) In [4]: a Out[4]: array([1, 3, 4, 2]) Note that alsonumpy allows the seed to be set. For example, setting the seed to 10 (asabove),couldbedoneby np.random.seed(10) The fact that a module by the name random is found both in the standard Python libraryrandomand innumpy, calls for some alertness. With proper import statements (discussed in Sect.1.4.1),however, there shouldbenoproblem. For more details about thenumpy functions for pseudo-randomnumbers, check out the documentation(https://docs.scipy.org/doc/). 2.5 Exercises Exercise2.1: InteractiveComputingofVolume Redothe task inExercise1.2byusingPythoninteractively.Comparewithwhatyou gotpreviously fromthewrittenprogram. Exercise2.2: InteractiveComputingofCircumferenceand Area Redothe task inExercise1.3byusingPythoninteractively.Comparewithwhatyou gotpreviously fromthewrittenprogram. Exercise2.3:UpdateVariableatCommandPrompt InvokePython interactivelyandperformthe followingsteps. 1. Initializeavariablex to2. 2. Add3 tox. Printout the result. 3. Printout the resultofx + 1*2and(x+1)*2. (Observehowparenthesesmakea difference). 4. Whatobject typedoesx refer to? Exercise2.4:Multiple StatementsonOneLine a) Theoutputproducedby the followingtwo lineshasbeenremoved.Canyoutell, fromjust reading the input,what theoutputwas in eachcase? 15 Instead of an array, we can also use a list, see Sect.5.1.