Hey guys, I cross post this from stackoverflow, initially I thought there was a problem in my code, but in the end it’s something wrong with Python in Dynamo. You can see my pose here:
In brief, I’m trying to calculate the perpendicular distance between a point a and a line, and Dynamo gave me a value that’s very large (27111), while the correct value (returned by other python IDE) is 103. Anyone know why is that? Is this a bug?
I’m using Dynamo 1.3.2 in Revit 2016.
import math
#The inputs to this node will be stored as a list in the IN variables.
dataEnteringNode = IN
def dot(v,w):
x,y,z = v
X,Y,Z = w
return x*X + y*Y + z*Z
def length(v):
x,y,z = v
return math.sqrt(x*x + y*y + z*z)
def vector(b,e):
x,y,z = b
X,Y,Z = e
return (X-x, Y-y, Z-z)
def unit(v):
x,y,z = v
mag = length(v)
return (x/mag, y/mag, z/mag)
def distance(p0,p1):
return length(vector(p0,p1))
def scale(v,sc):
x,y,z = v
return (x * sc, y * sc, z * sc)
def add(v,w):
x,y,z = v
X,Y,Z = w
return (x+X, y+Y, z+Z)
def pnt2line(pnt, start, end):
line_vec = vector(start, end)
pnt_vec = vector(start, pnt)
line_len = length(line_vec)
line_unitvec = unit(line_vec)
pnt_vec_scaled = scale(pnt_vec, 1.0/line_len)
t = dot(line_unitvec, pnt_vec_scaled)
if t < 0.0:
t = 0.0
elif t > 1.0:
t = 1.0
nearest = scale(line_vec, t)
dist = distance(nearest, pnt_vec)
nearest = add(nearest, start)
return (dist,nearest)
p0=[-93011.819, 510935.550, 84400.000]
p1=[-94493.434, 510660.112, 84400.000]
p2=[-80724.587, 514213.145, 84400.000]
result=pnt2line(p0,p1,p2)
#Assign your output to the OUT variable.
OUT = result
Worked fine for me…