GO TO statements- Fortran to Matlab - 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 while loops but I think I need something else for them end the search). Any help would be greatly appreciated.
vmax = -1.0E+15
amax_G = -1
askipR = REAL(ac_max - ac_min)/REAL(intA)
askip = CEILING(askipR)
DO acc0 = 1,intA+1
acc = ac_min + askipR * (acc0-1)
cons = ( x1 - grida2(acc) ) / onetauc
IF (cons<0.0) GOTO 102
vtemp = utilR(cons) + one_sv * utilB(acc)
IF (vtemp>vmax) THEN
vmax = vtemp
amax_G = acc
ELSE
GOTO 102
ENDIF
ENDDO ! acc0
102 continue
IF (askip<2) GO TO 109
askip = askip/2
IF (amax_G>ac_min) THEN
acc = amax_G - askip
cons = ( x1 - grida2(acc) ) / onetauc
IF (cons<0.0) PRINT *,'WARNING: NEGATIVE CONS # ASEARCH_Rx'
vtemp = utilR(cons) + one_sv * utilB(acc)
IF (vtemp>vmax) THEN
vmax = vtemp
amax_G = acc
GOTO 102
ENDIF
ENDIF
IF (amax_G < ac_max) THEN
acc = amax_G + askip
cons = ( x1 - grida2(acc) ) / onetauc
IF (cons<0.0) GO TO 102
vtemp = utilR(cons) + one_sv * utilB(acc)
IF (vtemp>vmax) THEN
vmax = vtemp
amax_G = acc
ENDIF
ENDIF
GOTO 102
109 CONTINUE
vfunR(jc,ac,sc) = vmax ! jc=Nj
afunR_G(jc,ac,sc) = amax_G ! jc=Nj

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