yet another question on Mathematica numerical, how to force it to use single precision?

How can I make Mathemtica give me the same digits to this little sum below
as I get from Fortran or Matlab?
I tried using just N[], which is should use machine precision. I want to
tell it to do the computation in "single precision", i.e. 32 bit as compared
to double precision.

Could some one remind me how to do this?

This is the Mathematica code

---------------------
In[95]:= s = Sum[N[1/k^2], {k, 1, 20000}]
Precision[s]
Accuracy[s]

Out[95]= 1.644884068098209
Out[96]= MachinePrecision
Out[97]= 15.738454476026273
----------------------

This is what I get from Fortran

PROGRAM main
IMPLICIT NONE
REAL :: s
INTEGER :: n,MAX

s = 0.0;
MAX = 20000;

DO n = 1,MAX
s = s + (1./n**2);
END DO

WRITE(*,*), 'sum', s
END PROGRAM main

$ f77 sum_problem.f
$ ./a.exe
sum 1.64472532

------------------------------

This is what I ge from Matlab (by forcing matlab to use single precision

format long g;
s=single(0);
MAX = 20000;
for i=1:MAX
s=s+(1/i^2);
end
s

s =
1.644725

So, Fortran and Matlab generate the same first 6 digits beyond the decimal
point. I want Mathematica to generate those same digits.

Any ideas?

thanks,
Nasser


.

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