[Numpy-discussion] "Lists" and "Join" function needed

[Warren Weckesser]

On 5/4/13, Bakhtiyor Zokhidov <bakhtiyor_zokhidov at mail.ru> wrote:
>
> Hi,
> I have the following code which represents intersected point of each cell in
> the given two points, A(x0,y0) and B(x1,y1).
>
> def intersected_points(x0, x1, y0, y1):
> # slope
> m = (y1 - y0 )/( x1 - x0)
> # Boundary of the selected points
> x_ceil = ceil( min (x0, x1 ))
> x_floor = floor( max(x0, x1))
> y_ceil = ceil( min(y0, y1))
> y_floor = floor( max(y0, y1))
> # calculate all intersected x coordinate
> ax = []
> for x in arange(x_ceil, x_floor + 1, 1):
> ax.append([ x, m * ( x - x0 ) + y0 ])
> # calculate all intersected y coordinate
> for y in arange(y_ceil, y_floor + 1, 1):
> ax.append([ ( y - y0 ) * ( 1./m ) + x0, y ])
> return ax
>
> Sample values: intersected_points(1.5,4.4,0.5,4.1)
> Output: [[2.0, 1.1206896551724137], [3.0, 2.3620689655172411], [4.0,
> 3.6034482758620685], [1.9027777777777779, 1.0], [2.7083333333333335, 2.0],
> [3.5138888888888893, 3.0], [4.3194444444444446, 4.0]]
>
> The output I got is unsorted values, so, for each cell coordinates, where
> line crosses:
> BUT, The result I want to get should be something in increased orders
> like: (x0,y0), (x1,y1), (x2,y2), (x3,y3)
> where x0, y0 - intial, x1,y1 - final point. Other values are intersected
> line coordinates!
>
> Any answers will be appreciated,
>
> --  Bakhtiyor Zokhidov


You also asked this question on stackoverflow
(http://stackoverflow.com/questions/16377826/distance-for-each-intersected-points-of-a-line-in-increased-order-in-2d-coordina).
 I've posted an answer there.

Warren