matlab编程与工程应用 课后答案-第2章

1、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*O3%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)6fpri

2、ntf('不指定宽度: %fn',12345.6789)不指定宽度: 12345.678900fprintf('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: 12345.6789fprintf('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: 12345.68fprintf('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: 12345.6789fprintf('2个字符宽度

3、，4个小数位: %2.4fn',12345.6789)2个字符宽度，4个小数位: 12345.67897fprintf('不指定宽度：%int16n',12345)不指定宽度：12345nt16fprintf('不指定宽度：%dn',12345)不指定宽度：12345fprintf('5个字符宽度：%5dn',12345)5个字符宽度：12345fprintf('8个字符宽度：%8dn',12345)8个字符宽度： 12345fprintf('3个字符宽度：%3dn',12345)3个字符宽度：123458

4、x = 12.34;y = 4.56;fprintf('x is %.3fn',x)x is 12.340fprintf('x is %2.0fn',x)x is 12fprintf('y is %.1fn',y)y is 4.6fprintf('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

5、9;,area)10string = input('what is your name?','s');fprintf('WoW,your name is %sn',string)11string = input('enter your string:','s');fprintf('your string was:''%s''n',string) %输出单引号是应采用''格式12v = input('enter the flow in m3/s:

6、');fprintf('a flow rate of %.3f meters per secnis equivalent to %.3f feet per secn',v,v/0.028)13incomeyear = 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,incomeye

7、ar*0.1,incomeyear*0.08/12,incomeyear*0.1/12)14wight = input('wight of plant: ');area = input('area of wing: ');fprintf('W/A: %f kg/m2n',wight/area)15x= 10;y =22;plot(x,y,'g+')16x = -2:0.1:2;plot(x,exp(x)xlabel('x')ylabel('y')title('y=ex')17x =

8、1:5:100;y = sqrt(x);figure(1)plot(x,y)figure(2)bar(x,y)18略19x1 = linspace(0,pi,10);figure(1)plot(x1,sin(x1)x2 = linspace(0,pi,100);figure(2)plot(x2,sin(x2)20mat = 1000 2000 3000 5000 10000;288 281 269 256 223'x = mat(:,1);y = mat(:,2);plot(x,y)xlabel('high')ylabel('tempture')titl

9、e('high-tempture')21mat1 = 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;randfile22mat = rand(2,3)*4-1;save testtan.dat mat -ascii;load testtan.dat;mattan = tan(testtan)23mat = 89 42 49 55 72 63 68 77 82 76 67;

10、90 45 50 56 59 62 68 75 77 75 66; 91 44 43 60 60 60 65 69 74 70 70save hightemp.dat mat -ascii;load hightemp.dathightemp(:,1) = hightemp(:,1)+1900;hightempsave y2ktemp.dat hightemp -ascii24%24 Calculates y as a function of xfunction y = fn(x)y = x3-4*x2+sin(x);25%25 Converts from MWh to GJfunction g

11、j = mwh_to_gj(mwh) gj = 3.6*mwh;26%26 converta from inch/h to meter/sfunction meter_sec = converta(inch_hour) meter_sec = inch_hour*5280*0.3048/3600;27function Tn = fn27(P,i,n) Tn = P*(1+i)*n;28略29function V = fn29(Pt,Ps) V = 1.016*sqrt(Pt-Ps);30function THR = fn30(A)THR = (220-A)*0.6;31function out

12、date = 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);f

13、printf('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 xfunction outdate =

14、 pickone(x)outdate = randi(x(1) x(end),1,1);36function outdate = vecout(x)outdate = x:1:x+5;37%37b = 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sindfprintf('t

15、he third side is %.3fn',a)38略39%39mat = 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 -ascii40%40costssales = 1100 800; 1233 650; 1111 100