Why my loop print every results even though im not using printf

Question

Why my loop print every results even though im not using printf. this is my coding. the result is print as matrix for every loop that been executed

r1=0.963;
r2=0.764;
r3=0.528;
r4=1.815;
r5=0.778;
phi1=0*(pi/180);
phi2l=0*(pi/180);
phi2u=90*(pi/180);
phi2ro=90*(pi/180);
printf("    phi-1     phi-2     phi-3     x-p     y-p\n");
printf("--------------------------------------------------\n");
do
  phi2r=((phi2l+phi2u)/2); #CALCULATE PHI2R
  fphi2l=((r1*cos(phi1)+r2*cos(phi2l)-r4)^2+(r1*sin(phi1)+r2*sin(phi2l))^2-(r3^2)); #EXECUTE FUNCTION USING PHI2L
  fphi2r=((r1*cos(phi1)+r2*cos(phi2r)-r4)^2+(r1*sin(phi1)+r2*sin(phi2r))^2-(r3^2)); #EXECUTE FUNCTION USING PHI2R
  check=fphi2l*fphi2r; #CALCULATE VALUE FOR CONDITION
  if(check<0)
  {
    phi2u=phi2r;
  }
  endif
  if(check>0)
  {
    phi2l=phi2r;
  }
  endif
  error=abs(phi2r-phi2ro)/phi2r; #CALCULATE ERROR
  phi2ro=phi2r;
until(error<10^-8)
phi2=phi2r;
phi3=asin((r1*sin(phi1)+r2*sin(phi2))/r3);
phi3c=acos((r1*cos(phi1)+r2*cos(phi2)-r4)/r3);

Answer 1

You have a syntax "error" in your if blocks. In octave you don't need to enclose the if "block" in braces. What you're written effectively wraps that assignment inside a 'cell'. And because the 'cell' statement isn't terminated by a semicolon (note that the semicolon is inside the cell!), the resulting cell gets printed on the terminal.

You can just do this instead:

if check > 0
  phi2l = phi2r;
endif