如何刪除或MATLAB終止行

Question

嗨，大家好，我想刪除或終止含d> 8，這裏是我的代碼

fileID = fopen('d.csv','w'); 


fprintf(fileID, ' a, b, d \n'); 
for a = -3:3 
    for b= -3:3 
      d = a^2 + b^2; 
      if d > 8 
       break; 
      else 
      fprintf(' %d, %d, %d, \n',a,b,d); 
      end 
    end 
end 

fclose(fileID); 

我用休息來刪除行的行，突破僅適用於循環或while循環但它不起作用，輸出顯示標題，請幫助。

Answer 1

vectorized怎麼樣讓事情做得更快！下面列出的代碼可能是用來量化一個偉大的工具這樣一個方法 - bsxfun，然後寫入到輸出文件與另一個快速I/O書寫工具 - dlmwrite -

file = 'results.txt'; %//'# Path to output text or csv file 
offset = 3;   %// offset factor used inside the loops 
comp = 8;    %// value to be compared against for D 

%// Find all possible d values 
dvals = bsxfun(@plus,[-offset:offset]'.^2,[-offset:offset].^2) %//' 

%// Find a and b values satisfying the comparison criteria 
[avals,bvals] = ind2sub(size(dvals),find(dvals <= comp)) 

%// Write the values to the output file with dlmwrite 
dlmwrite(file,' a, b, d ','') 
dlmwrite(file,[avals(:)-offset-1 bvals(:)-offset-1 dvals(dvals<=comp)],'-append') 

驗證結果 -

>> type(file) 

a, b, d 
-2,-2,8 
-1,-2,5 
0,-2,4 
1,-2,5 
2,-2,8 
-2,-1,5 
-1,-1,2 
0,-1,1 
1,-1,2 
2,-1,5 
-2,0,4 
-1,0,1 
0,0,0 
1,0,1 
2,0,4 
-2,1,5 
-1,1,2 
0,1,1 
1,1,2 
2,1,5 
-2,2,8 
-1,2,5 
0,2,4 
1,2,5 
2,2,8 

---

對於循環代碼的新手 -

fprintf(fileID, ' a, b, d \n'); 
for a = -3:3 
    for b= -3:3 
     d = a^2 + b^2; 
     if d <= 8 
      fprintf(fileID,' %d, %d, %d, \n',a,b,d); 
     end 
    end 
end 
fclose(fileID);