Assuming 8 bytes per number, representing this array would need about:
2 ^.*/8 50 2 1090 1376
30.1602
30 bits of address space. Or, slightly over 1 gigabyte.
Add another factor of 5 for intermediate results... you probably need
a 64 bit implementation of J to run this code. (If that is what
yes I guess they're overly larger
The size of the result should be 50 x (2 x 1090*1376)
normal right?
maybe I have to change the strategy
Raul Miller-4 wrote:
>
> limit error typically means you are doing something different from
> what you think you are doing. Here's an example:
>
>i.
yes I guess they're overly larger
The size of the result should be 50 x (2 x 1090*1376)
normal right?
maybe I have to change the strategy
Raul Miller-4 wrote:
>
> limit error typically means you are doing something different from
> what you think you are doing. Here's an example:
>
>i.
limit error typically means you are doing something different from
what you think you are doing. Here's an example:
i.1+i.1+i.9
|limit error
I would probably start by examining the values used in the expression
which is getting this error. They are probably overly large, or
something.
>.
Very impressive.. thanks
I got all the unknowns.
I was going to include more things in the "sovleeqn" but I get "limit error"
After getting unknowns (a-h) I have to transform them back to the image with
some formula.
I followed your outline to create "solveeqn"
solveeqn=: 4 : 0
...
...
OK. I will outline a solution that you can fill in
Given the table A:
u1 v1 (x1 y1) ... repeated for many images
0. Create a verb 'solveeqn' that will solve one system, given
x = 200x2 array of u v
y = 2x200 array of x y
1. Create
uv =. 2 {."1 A
xy =. 2 }. |: A
2. Run
_2 uv&sol
My fault again. I had to make difference between y and yi
a-h will be derived in least-square sense, which are the final result. There
are 50 x (a-h) unknowns correspond to each equation.
The structure of actual data is:
u1 v1x1,1 y1,1 ... x1,50 y1,50
u2 v
From this I'm pretty sure that the problem can be solved without loops
or boxing, but I still have no idea what any of the values
u v y xi a-h
mean, or what their shapes are. Also, the description uses 'row' and
'column' to describes things that seem to be matrices rather than row
and column
Sorry for confusion. The "a" matrix is not what you've described.
I have to solve 49 independent equations
y = a1.x1
y = a2.x2
...
y = a49.x49
"y" in all the equations is fixed which is corresponds to the first column
of data and number of unknowns in "x" depends on the design matrix "a" that
has
You might want to go through the linear algebra lab LAPACK in your J
distribution,
or the J lab companion to Schaums "Linrear Algebra" textbook, also in the J
distribution
Have you looked at:
http://www.jsoftware.com/svn/base/trunk/math/matrix/linear.ijs
http://www.jsoftware.com/wsvn/addons/trunk/
I'm confused.
In your first message, you said that you are solving y=ax, and that
you had data for y and for a, and that y's shape was 200 while a's
shape was 200 49 (which would suggest that x has shape 49). And I
thought you were asking for help in extracting the data from a textual
format.
In
The content of the text is numbers (x y positions). I trimmed all the
unnecessary characters (like , ( ) = etc.) and what I got is a 200 x 50
matrix (or more precisely 200 x 100 because we have x and y). I managed to
get and solve the equation for the 2nd column but I need strategy for other
colum
On Sat, Sep 8, 2012 at 3:39 PM, pascha wrote:
> What I have been asking during past days was about making and solving linear
> equation (y = ax) from a data text file. With your help I achieved to make
> one equation from the data but there are 49 other equation left which I am
> gonna make it som
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