matlab 概率图纸代码 正态分布 对数正态分布 伽马分布

R=xlsread('工程概率4',6,'A1:B20') x1=R(:,1)'; k1c=R(:,2)'; ms=-log(-log(x1)); A=polyfit(ms,k1c,1); y=polyval(A,ms); %%%数据分析，求出s=0分位处的值，并求s=1分位处的值，联合求解斜率 mmiu=0; u=polyval(A,mmiu); m1=1; k=polyval(A,m1)-polyval(A,mmiu); %%%作图 plot(ms,k1c,'x',ms,y,'b'); grid on; %%%修改横轴坐标为Gumbel分布 %%%xticks就是你要在哪些值处显示刻度，xticklabels就是指定显示为什么 % axis([-2 -log(-log(0.999)) 0 9]); xticks([-log(-log(0.001)) -log(-log(0.01)) -log(-log(0.1))... -log(-log(0.2)) -log(-log(0.3)) -log(-log(0.4))... -log(-log(0.5)) -log(-log(0.7)) -log(-log(0.8))... -log(-log(0.9)) -log(-log(0.95)) -log(-log(0.97)) ... -log(-log(0.98)) -log(-log(0.99)) -log(-log(0.995))... -log(-log(0.9975)) -log(-log(0.999))]); xticklabels({'.001','.01','.10',' ','.30',' ','.50','.70','.80','.90','.95','.97','.98','.99','.995','.9975','.999'}); xticks1=xticks; xticks1y=11.2*ones(1,length(xticks1)); xticklabels1={' ','100','10','5',' ',' ','2',' ','5','10','20',' ','50','100','200','500','1000'}; text(xticks1-0.1,xticks1y,xticklabels1); grid on; xlabel('累计概率=m/(N+1)'); ylabel('风速'); %%%求解曲线斜率 u k 1/k