I would like to add a command to create a rectangle by area with fixed proportions (in the golden ratio). I did that little script in grasshopper, but I’d find it much more easier to have that as a command written in python. Could someone give me a hand with that?

So the main thing is to create a rectangle based on the area. A rectangle is “a * b”, because it should be in the golden ratio “b = a * 1.618”, so “A=a² * 1.618” therefore “sqrt(A/1.618) = a”.

In my example the area of the rectangle is the input, 25 sqm, based on the golden ratio the length and the width of the rectangle is 3,93/6,36.

Here is a quickie hack - will ask for area input and lower left corner point, then draws rectangle along world XY axes… More sophisticatation could be added of course… --Mitch

```
import rhinoscriptsyntax as rs
import math
def CreateGoldRect():
tol=rs.UnitAbsoluteTolerance()*10
area=rs.GetReal("Square area?",minimum=tol)
if area is None: return
pt0=rs.GetPoint("Lower left corner of rectangle")
if not pt0: return
gs=1.618
yval=math.sqrt(area/gs)
xval=yval*gs
pt1=rs.coerce3dpoint([pt0.X+xval,pt0.Y,pt0.Z])
pt2=rs.coerce3dpoint([pt0.X+xval,pt0.Y+yval,pt0.Z])
pt3=rs.coerce3dpoint([pt0.X,pt0.Y+yval,pt0.Z])
rs.AddPolyline([pt0,pt1,pt2,pt3,pt0])
CreateGoldRect()
```

1 Like

thank you Helvetosaur! Everything I wanted! One thing, how can I implement another option to 1.618? I want it to be the standard, but changable.

Edit: Another nice thing would be rounded numbers.

alright, it’s pretty straight forward. my outcome:

import rhinoscriptsyntax as rs

import math

def CreateGoldRect():

tol = rs.UnitAbsoluteTolerance() * 10

area = rs.GetReal(“Square area?”, minimum=tol)

if area is None: return

```
pt0 = rs.GetPoint("Lower left corner of rectangle")
if not pt0: return
gs = rs.GetReal("Ratio", 1.618)
yval = math.sqrt(area / gs)
xval = yval * gs
yvalr = round(yval, 1)
xvalr = round(xval, 1)
pt1 = rs.coerce3dpoint([pt0.X + xvalr, pt0.Y, pt0.Z])
pt2 = rs.coerce3dpoint([pt0.X + xvalr, pt0.Y + yvalr, pt0.Z])
pt3 = rs.coerce3dpoint([pt0.X, pt0.Y + yvalr, pt0.Z])
rs.AddPolyline([pt0, pt1, pt2, pt3, pt0])
```

CreateGoldRect()