I'm a CS major in university working on a programming project for my Calc III course involving singular-value decomposition. The idea is basically to convert an image of m x n dimensions into an m x n matrix wherein each element is a tuple representing the color channels (r, g, b) of the pixel at point (m, n). I'm using Python because it's the only language I've really been (well-)taught so far.
From what I can tell, Python generally doesn't like tuples as elements of an array. I did a little research of my own and found a workaround, namely, pre-allocating the array as follows:
def image_to_array(): #converts an image to an array
aPic = loadPicture("zorak_color.gif")
ph = getHeight(aPic)
pw = getWidth(aPic)
anArray = zeros((ph,pw), dtype='O')
for h in range(ph):
for w in range(pw):
p = getPixel(aPic, w, h)
anArray[h][w] = (getRGB(p))
return anArray
This worked correctly for the first part of the assignment, which was simply to convert an image to a matrix (no linear algebra involved).
The part with SVD, though, is where it gets trickier. When I call the built-in numPy svd function, using the array I built from my image (where each element is a tuple), I get the following error:
Traceback (most recent call last):
File "<pyshell#5>", line 1, in -toplevel-
svd(x)
File "C:\Python24\Lib\site-packages\numpy\linalg\linalg.py", line 724, in svd
a = _fastCopyAndTranspose(t, a)
File "C:\Python24\Lib\site-packages\numpy\linalg\linalg.py", line 107, in _fastCopyAndTranspose
cast_arrays = cast_arrays + (_fastCT(a.astype(type)),)
ValueError: setting an array element with a sequence.
This is the same error I was getting initially, before I did some research and found that I could pre-allocate my arrays to allow tuples as elements.
The issue now is that I am only in my first seme