X and Y Intercepts From Slopes - Python

Question

I have been working on a slope calculator that also finds x and y intercepts... how do I do this in Python? Thanks! Here is my current code:

def getSlope(x1, y1, x2, y2):
    slope = (y2-y1)/(x2-x1)
    return slope

def getYInt(x1, y1, x2, y2):
    s = getSlope(x1, y1, x2, y2)
    x = 0
    y = s*0 + yi

Solution 1

To find the y-intercept (b), you need to set x to one of the x values and y to one if the y values and solve:

y=mx+b
b=y-mx

The function could look like this:

m=getSlope(x1,y1,x2,y2)
b=y1-m*x1
return b

The coordinates of the point would be (0,b), so you can return that instead if you want.

Solution 2

For slope:

from __future__ import division
def getSlope((x1, y1), (x2, y2)):
    return (y2-y1)/(x2-x1)

For y-intercept

def getYInt((x1, y1), (x2, y2)):
    slope = getSlope((x1, y1), (x2, y2))
    y = -x1*slope+y1
    return (0, y)

---

>>> slope((7, 3), (2, 9))
-1.2
>>> getYInt((7, 3), (2, 9))
(0, 11.4)
>>> 

Comments

[KSFT]

This is almost exactly the same as the other two answers.

[Haleemur Ali]

yeah @KSFT. I think we all submitted our answers at around the same time, and as far as I'm aware, there's only one straightforward way to get the slope / intercept of a line.

[Alessandro Anderson]

Don't bother about the first function it is just to check if the other two are correct. Namasté