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

Bakhtiyor Zokhidov bakhtiyor_zokhidov at mail.ru
Sat May 4 14:18:09 EDT 2013

```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!