matlab编程与工程应用 课后答案-第2章

1 %计算空心球体积 r0 = 3; ri = 2; volume = 4*pi/3*(r03-ri3) 2%计算过氧化氢分子量 H = 15.9994; O = 1.0079; H2O2 = 2*H + 2*O 3%计算字符创长度 string = input(enter string: ,s); stringlength = length(string) %4 输入实数，fprintf 输出这个变量，格式为两位小数 num = input(enter a num: ); fprintf(The num is %.2fn,num) 6 fprintf(不指定宽度: %fn,12345.6789) 不指定宽度: 12345.678900 fprintf(10 个字符宽度， 4 个小数位: %10.4fn,12345.6789) 10 个字符宽度，4 个小数位: 12345.6789 fprintf(10 个字符宽度， 2 个小数位: %10.2fn,12345.6789) 10 个字符宽度，2 个小数位: 12345.68 fprintf(6 个字符宽度， 4 个小数位 : %6.4fn,12345.6789) 6 个字符宽度，4 个小数位: 12345.6789 fprintf(2 个字符宽度， 4 个小数位 : %2.4fn,12345.6789) 2 个字符宽度，4 个小数位: 12345.6789 7 fprintf(不指定宽度：%int16n,12345) 不指定宽度：12345nt16 fprintf(不指定宽度：%dn,12345) 不指定宽度：12345 fprintf(5 个字符宽度： %5dn,12345) 5 个字符宽度：12345 fprintf(8 个字符宽度： %8dn,12345) 8 个字符宽度： 12345 fprintf(3 个字符宽度： %3dn,12345) 3 个字符宽度：12345 8 x = 12.34; y = 4.56; fprintf(x is %.3fn,x) x is 12.340 fprintf(x is %2.0fn,x) x is 12 fprintf(y is %.1fn,y) y is 4.6 fprintf(y is %-6.1f!n,y) y is 4.6 ! 9 %计算矩形面积 x = input(enter length:); y = input(enter borad:); area = x*y; fprintf(area is %.2fn,area) 10 string = input(what is your name?,s); fprintf(WoW,your name is %sn,string) 11 string = input(enter your string:,s); fprintf(your string was:%sn,string) %输出单引号是应采用 格式 12 v = input(enter the flow in m3/s:); fprintf(a flow rate of %.3f meters per secnis equivalent to %.3f feet per secn,v,v/0.028) 13 incomeyear = input(enter your income per year: ); fprintf(the range of food expenditure per year %f%fnthe range of food expenditure per mounth %f%fn,incomeyear*0.08,incomeyear*0.1,incomeyear*0.08/12,incomeyear*0.1/12) 14 wight = input(wight of plant: ); area = input(area of wing: ); fprintf(W/A: %f kg/m2n,wight/area) 15 x= 10; y =22; plot(x,y,g+) 16 x = -2:0.1:2; plot(x,exp(x) xlabel(x) ylabel(y) title(y=ex) 17 x = 1:5:100; y = sqrt(x); figure(1) plot(x,y) figure(2) bar(x,y) 18 略 19 x1 = linspace(0,pi,10); figure(1) plot(x1,sin(x1) x2 = linspace(0,pi,100); figure(2) plot(x2,sin(x2) 20 mat = 1000 2000 3000 5000 10000;288 281 269 256 223; x = mat(:,1); y = mat(:,2); plot(x,y) xlabel(high) ylabel(tempture) title(high-tempture) 21 mat1 = randi(50,100,3,6) save randfile.dat mat1 -ascii; mat2 = randi(50,100,2,6) save randfile.dat mat2 -ascii -append; load randfile.dat; randfile 22 mat = rand(2,3)*4-1; save testtan.dat mat -ascii; load testtan.dat; mattan = tan(testtan) 23 mat = 89 42 49 55 72 63 68 77 82 76 67; 90 45 50 56 59 62 68 75 77 75 66; 91 44 43 60 60 60 65 69 74 70 70 save hightemp.dat mat -ascii; load hightemp.dat hightemp(:,1) = hightemp(:,1)+1900; hightemp save y2ktemp.dat hightemp -ascii 24 %24 Calculates y as a function of x function y = fn(x) y = x3-4*x2+sin(x); 25 %25 Converts from MWh to GJ function gj = mwh_to_gj(mwh) gj = 3.6*mwh; 26 %26 converta from inch/h to meter/s function meter_sec = converta(inch_hour) meter_sec = inch_hour*5280*0.3048/3600; 27 function Tn = fn27(P,i,n) Tn = P*(1+i)*n; 28 略 29 function V = fn29(Pt,Ps) V = 1.016*sqrt(Pt-Ps); 30 function THR = fn30(A) THR = (220-A)*0.6; 31 function outdate = fn31(n) outdate = sqrt(2*pi*n)*(n/exp(1)n; 32 %32 脚本 n = input(enter the number of units: ); Cn = costn(n); fprintf(the cost for %d units will be $%.2fn,n,Cn) %32 mygcost 函数 function Cn = costn(n) Cn = 5*n2-44*n+11; 33 %33 脚本 rain = input(enter the rain: ); snow = fn33(rain); fprintf(the snow is %fn,snow) %33 调用函数 function snow = fn33(rain) snow = rain*6.5; 34 %34 脚本 s = input(enter long_side: ); V = fn34(s); fprintf(volume is %.2fn,V) %34 函数 function V = fn34(s) V = sqrt(2)*s3/12; 35 %35 pickone(x) returns a random element from vector x function outdate = pickone(x) outdate = randi(x(1) x(end),1,1); 36 function outdate = vecout(x) outdate = x:1:x+5; 37 %37 b = input(enter the first side: ); c = input(enter the second side: ); alpha = input(enter the angle between them: ); a = sqrt(b2+c2-2*b*c*cosd(alpha); %切记这里用 sind fprintf(the third side is %.3fn,a) 38 略 39 %39 mat = 90.5792 27.8498 97.0593; 12.6987 54.6882 95.7167; 91.3376 95.7507 48.5376; 63.2359 96.4889 80.0280 9.7540 15.7613 14.1886; save floatnums.dat mat -ascii; load floatnums.dat; floatnums = round(floatnums) save intnums.dat floatnums -ascii 40 %40 costssales = 1100 800; 1233 650;