Re: least square solution of b = A * x with a very huge A matrix

[andrea console]

Thank you all.

In this example the matrices size is:

A: 1072452 X  323136 (sparse)

b:  1072452  X 1

c:  323136 X 1

This is the file (67MB): https://docs.google.com/file/d/0B4nOH7xkcKiabkdSNktLT0xhYjg/edit?usp=sharing

I didn't save it as blocks because, before computation, I have to remove some rows (and corresponding elements in b array), so the block structure is not preserved

2013/5/30 c. <address@hidden>

On 30 May 2013, at 10:22, "Abbott, Ben" <address@hidden> wrote:

> On May 30, 2013, at 4:08 PM, andrea console wrote:
>
>> Il giorno giovedì 30 maggio 2013, Nir Krakauer <address@hidden> ha scritto:
>>> Is it possible to send a working (or nonworking, as the case may be) example?
>>
>> Do you need the entire program with related data source files or can I attach the A and b matrices (please tell me how)?
>
> Just put the A and b matrices in to a file and zip it up
>
>       save example.mat A b
>       zip example.zip example.mat
>
> Then put the zipped file somewhere it can be accessed. Perhaps Dropbox, GoogeDrive, or some other convenient place.
>
> Ben

Actually, as you said your matrices have block structure it would probably be useful in studying your problem
if you could save the blocks separately in those files, e.g.:

A_blocks{1,1} = … ;
A_blocks{1,2} = … ;
A_blocks{1,3} = … ;
…

b_blocks{1} = … ;
b_blocks{2} = … ;
b_blocks{3} = … ;
…

save example.mat A_blocks b_blocks

c.