problem in initializing sparse matrix

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vijay
vijay 2013-5-8
I encountered this strange counter intuitive thing, a = 150e-6; b = 1e3; c = 1e4;
d = a*b*c; % now d = 1500 is definitely an integer mathematically but A = sparse(2*d,2*d) says "Error using ==> sparse Sparse matrix sizes must be non-negative integers less than MAXSIZE as defined by COMPUTER. Use HELP COMPUTER for more details."
d is displayed as 1.500000(couple of more zeors)e+003. it is equal to 1500. i tried forcing by int32(); then another error comes. but initializing A = sparse(2*1.5e3,2*1.5e3) does fine. any clue what i'm missing. many thanks for the help on this strange issue. I guess i'm missing some thing obvious but can't catch it.

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Youssef Khmou
Youssef Khmou 2013-5-8
hi,
it worked well, no problem and d=1500, try to use of these functions :
d=floor(d);
d=ceil(d);
d=round(d);
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vijay
vijay 2013-5-8
thanks a lot youssef,
It works with suggested functions. i include a more working error for future,
%%
density = 150e-6;
width = 10000;
length =1000;
temp_number= (density*width*length);
global_number= (temp_number)
A2 = sparse(2*global_number, 2*global_number);
%A3 = sparse(2*1.5000e+3,2*1.5000e+3); % this was fine
%%
A2 gives error, fixing to floor(A2) does fixes it. but still i'm not clear if this is bug of having different interpretation of integers. could you please say on what may be the reason for it. and why int32() was failing
Youssef Khmou
Youssef Khmou 2013-5-8
maybe the reason is : it is written in the documentation of 'int32()' that If the stored integer word length is too big for an int32 the returned value saturates to an int32, "saturates", but not rounded .

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