[Tutor] Converting a numpy matrix to a numpy array
steve at pearwood.info
Thu Mar 31 16:25:19 CEST 2011
David Crisp wrote:
> I have a 2d matrix representing the X the Y and the Z value of a
> point. I wish to convert that matrix to an array. What is a good
> way of doing so?
It's not clear what this matrix actually is. Is this from a text file?
What are the X's and O's (letter o)? Are they meant to be place-holders
for something else, or literally letter X and letter O?
If placeholders, what are they placeholders for? And if literally X and
O, what are you expecting to do with them in numpy, which expects
> I want to convert that to a 2d array which looks like:
What you are describing is not a two dimensional array. It is a
one-dimensional list, each item of which includes 2D coordinates as
explicit data. You almost certainly do not want that! Working with
numpy, you want to use a numpy two dimensional array that looks
something like this:
[ [ x o o o o o ]
[ x o o o o o ]
[ o x x x x x ]
[ o o o o o o ]
[ o o o o o x ]
[ o o o o o x ] ]
where the coordinates are implied. I have borrowed Python list syntax 
for the array. Each row is a [...] and the columns are read down the rows.
Unfortunately, I'm not using my usual computer, so I don't have access
to numpy at the moment. More detail will have to follow later.
More information about the Tutor