http://maggie74.blogbus.com/logs/59768118.html

matlab画图能力很强，而且其可编程性给处理问题带来很大方便，我尝试将fluent导出的ASCII数据导入matlab处理，原代码如下：

%打开文件并读入数据
fid=fopen('post','r');
name2=input('input the file name\n','s')
fgetl(fid)
data1=fscanf(fid,'%f %f %f %f %f',[5 inf]);
fclose(fid);
fid=fopen(name2,'r');
fgetl(fid);
data2=fscanf(fid,'%f %f %f %f %f',[5 inf]);
fclose(fid);
%对数据按坐标升序排列
xudata1=sortrows(data1',2);
xudata2=sortrows(data2',2);
xudata1=xudata1';xudata2=xudata2';
%找出sym和avg数据
maxr=max(xudata1(3,:));stp=0.0002;%y坐标最大值，求avg时候的x步长
avg1=zeros(2,round(1+0.02/stp));avg1(1,:)=0:stp:0.02;avg2=avg1;%对avg坐标赋初值
j=1;j2=1;jj=1;%j记录avg的当前index；j2记录avg(j)中第一个加入的xudata的index；jj记录sym的当前index
for i=1:length(xudata1)
     if xudata1(3,i)>maxr-0.00004
     sym1(1,jj)=xudata1(2,i);sym1(2,jj)=xudata1(5,i);
     sym2(1,jj)=xudata1(2,i);sym2(2,jj)=xudata2(5,i);
     jj=jj+1;
     end
      mii=fix((xudata1(2,i)+stp/2)/stp)+1;
     avg1(2,mii)=avg1(2,mii)+xudata1(5,i);
     avg2(2,mii)=avg2(2,mii)+xudata2(5,i);
     if mii>j|i==length(xudata1)
     avg1(2,j)=avg1(2,j)/(i-j2);
     avg2(2,j)=avg2(2,j)/(i-j2);
     i-j2
     j=j+1;j2=i;
     end
end
%绘图
figure(1)
plot(sym1(1,:),sym1(2,:),sym2(1,:),sym2(2,:))
figure(2)
plot(sym1(1,:),sym1(2,:),sym2(1,:),sym2(2,:),avg1(1,:),avg1(2,:),avg2(1,:),avg2(2,:));
legend('sym1','sym2','avg1','avg2');
hold on
plot(sym1(1,:),sym2(2,:)./sym1(2,:),avg1(1,:),avg2(2,:)./avg1(2,:));
legend('symrate','avgrate');
fid=fopen(['tec' name2],'w');
fprintf(fid,'TITLE = "heat transfer coefficient" \nVARIABLES = "x/d", "yta or rate" \nZONE T="sym", I=%d, F=POINT\n',length(sym2));
fprintf(fid,'.6f .6f',sym2);
fprintf(fid,'ZONE T="avg", I=%d, F=POINT\n',length(avg2));
fprintf(fid,'.6f .6f',avg2);
fclose(fid)
%用tecplot格式输出
fid=fopen('tecpost','w');
fprintf(fid,'TITLE = "heat transfer coefficient" \nVARIABLES = "x/d", "yta or rate" \nZONE T="sym", I=%d, F=POINT\n',length(sym1));
fprintf(fid,'.6f .6f',sym1);
fprintf(fid,'ZONE T="avg", I=%d, F=POINT\n',length(avg1));
fprintf(fid,'.6f .6f',avg1);
fclose(fid)