Re: Redirecting output to file
- To: mathgroup@smc.vnet.net
- Subject: [mg12420] Re: [mg12284] Redirecting output to file
- From: "V. Nandagopal" <nandgopa@math.tifr.res.in>
- Date: Thu, 14 May 1998 11:15:29 -0400
> In[2]:= Length[e]
> Out[2]= 80
>
> So let's see how many elements your result will have.
>
> In[4]:= Binomial[80,4]
> Out[4]= 1581580
>
> Each element is in effect a matrix: a list of four lists of five
> integers. So above and beyond the list overhead we'll need to store
> twenty integers. How much space does an integer occupy?
>
> In[5]:= ByteCount[Range[100]]
> Out[5]= 1620
>
> Probably 16 bytes, with the remaining 20 for list overhead. Let's
> double-check.
>
> In[6]:= ByteCount[Range[200]]
> Out[6]= 3220
>
> 16 bytes per integer it is. Do we save anything when the lists contain
> the same integers?
>
> In[7]:= ByteCount[Table[1, {100}]]
> Out[7]= 1620
>
> No such luck. So storage for your result will be larger than
>
> (16 bytes-per-integer) * (20 integers-per-element) * (1.5Meg elements)
>
> Actually the product of the first two, 320, can be replaced by 416:
>
> In[8]:= ByteCount[Table[i+j, {i,4}, {j,5}]]
> Out[8]= 416
>
> So you will need around 600 M to contain the result. I do not know
> whether this size is cause for the behavior you saw, just thought I
> would point out that you are trying to write a very large object to a
> file. Possibly it produces the object but dies in formatting.
===========================================================================
> Daniel Lichtblau,
> Wolfram Research
Dear Mr. Daniel Lichtblau,
Thank you for the prompt response. I did think that the size could be
the problem. Actually, I need to add an extra row comprising of
{1,1,1,1,1} to all the matrices I get from the result of the
computation and then I need to compute the determinants, rank and the
minors of this huge number of 5x5 matrices.
Is there anyway I can do this on my machine?
Thanking you once again,
With best regards,
V. Nandagopal
School of Mathematics
Tata Institute of Fundamental Research
Colaba, Bombay 400 005, India
e-mail: nandgopa@math.tifr.res.in