牙膏销售量模型

>>[b,bint,r,rint,state]=regress(y,x,0.05);
>> x3=5:0.1:8;
>>> plot(x3,y2)
>> hold on;
>> plot(x3,y3)
>> xlabel('广告费/百万元');ylabel('销量/百万支');
>> title('不同价格差下广告费对销量的影响');
>> text1=text(6.9, 8.5, 'x2=0.1');
>> text2=text(6.3, 8.9, 'x2=0.1');
>> delete(text2);
>> text2=text(6.5, 8.7, 'x3=0.3');
>> delete(text2);
>> text2=text(6.2, 8.7, 'x3=0.3');
>> grid on
>> plot(x3,y2)
>> hold on;
>> plot(x3,y3)
>> xlabel('广告费/百万元');ylabel('销量/百万支');
>> title('不同价格差下广告费对销量的影响');
>> text1=text(6.9, 8.5, 'x2=0.1');
>> text2=text(6.2, 8.7, 'x3=0.3');
>> grid on