GO TO statements- Fortran to Matlab

Question

I have been trying really hard to convert this grid search code from Fortran to Matlab, however I am not able to properly incorporate the GO TO statements (I am trying to use wh

Answer 1

You have two types of control-flow implemented with your GOTO statement:

Type 1: breaking out of a loop

The GOTO statement is used to break out of the DO-loop:

    DO acc0 = 1,intA+1  
        ! some code
        IF (cons<0.0) GOTO 102
        ! some more code
    END DO
102 continue

As you notice, if cons < 0.0 the GOTO statement states to move to label 102 which is located just outside of the DO-loop. In matlab is nothing more than a simple break in a for-loop:

for acc0=1:intA+1
  % some matlab code
  if (cons < 0.0)
    break
  end
  % some more matlab code
end

Type 2: creating a loop

While the loop is not explicitly written, the following code creates something that can be translated as a while loop:

    ! This is the start of the loop
102 continue
    ! This is the condition to exit the loop <<==
    IF (askip<2) GO TO 109
    ! stuff
    ! This is a condition to restart the loop    <<==
    IF (vtemp>vmax) THEN
         vmax   = vtemp
         amax_G = acc
         GOTO 102
    ENDIF
    ! stuff
    ! This is another condition to restart the loop   <<==
    IF (cons<0.0) GO TO 102
    ! stuff
    ! This is the end of the loop, asked to restart it  <<==
    GOTO 102
    ! This is outside of the loop
109 CONTINUE

In the end, you translate this as:

while (askip >=2)
   % stuff
   if (vtemp > vmax)
        vmax = vtemp
        amax_G = acc
        continue
   end
   % stuff
   if (cons < 0.0)
      continue
   end
   % stuff
end