Conversion of a Fortran Equation to Matlab

Hello,

I need some help converting a relatively simple equation from Fortran to Matlab. I'm fairly fluent in Matlab but I haven't really had a chance to mess with Fortran. The code is designed to convert heat flux into a temperature value. From what I can tell, the equation works iteratively in a loop going number by number. Am I right in saying 'DO 4' creates an array called TCALC that are just filled with the first number from the array TEXP. Then, 'DO 5' works backwards by -1 increments from 200 (TIMEF = 200) to 1 and each time the loop repeats, N and J decrease by 1 until they get to 1. Within this loop, all the numbers gointo the ELSE equation until it gets to the first number in the array and it goes to the THEN equation. It seems like there is a better way to write this with sum perhaps. For reference, in the original document this is equation 6 and the Fortran code is included at the bottom of the document. https://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19940031900.pdf

DO 4 N = 1, TIMEF

TCALC(N) = TEXP(1)

DO5 J=N, 1,-1

IF (J.EQ.1) THEN

TCALC(N) = TCALC(N) - 2.*SQRT(ALPHA)/K/SQRT(PI)*QEXP(J) + *(SQRT(((N-.5)-(J-.5))*.02)-SQRT((N-.5)*.02))

ELSE

TCALC(N) = TCALC(N) -2.*SQRT(ALPHA)/K/SQRT(PI)*QEXP(J) + *(SQRT(((N-.5)-(J-.5))*.02)-SQRT(((N-.5)-(J- 1.5))*.02))

ENDIF

Answer 1

[Alan Stevens]

This is the correponding MATLAB structure:

for N = 1:TIMEF   
    
    TCALC(N) = TEXP(1);
    
    for J = N:-1:1
        
        if J==1
            TCALC(N) = TCALC(N) - ...;
        else
            TCALC(N) = TCALC(N) - ...;
        end 
        
    end % of for J = N:-1:1 loop (FORTRAN line labelled 5)
    
    fprintf(...)
    
end % of for N = 1:TIMEF loop (FORTRAN line labelled 4)

[Eric Cheatwood]

Thank you so much.