slope of a line

Naman2007

I have a text file containing the following content:

0 12
1 15
2 6
3 4
4 3
5 6
6 12
7 8
8 8
9 9
10 13

the first column specifies the x coordinate of a point and second column specifies the y coordinate.i need to read this file and find slope between all points. like first i find slope between (0,12) and (1,15) and then between (0,15) and (2,6) and so on.i am basically building a wpf application.can anyone help?

Abhinav S

The basic forumula for a slope is (y2 - y1) / (x2 - x1). Since you have all the co-ordinates, you can put them into an array and then run a loop over the array. You can also input them via a textbox on WPF.

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Naman2007

i tried to put x and y coordinates in two different arrays but don't understand how to write a code that calculates the slope between points and displays them in a textbox. i have written the following code snippet:

var r = File.ReadAllLines(path)
.Select(line => line.Split(' '))
.Select(arr => new
{
Column0 = Int32.Parse(arr[0]),
Column1 = Int32.Parse(arr[1])
// etc
})
.ToArray();
int[] column0 = r.Select(x => x.Column0).ToArray();
int[] column1 = r.Select(x => x.Column1).ToArray();

Abhinav S

Try

for (int i=0; i<=column1.Count - 2;i++)
{
float slope = (column1[i+1] - column1[i])/(column0[i+1] - column0[i])
}

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Lost User

Shouldn't you cast at least one of the operands of the division to float then?

Naman2007

i'm getting 'divide by zero' exception here.what is the method to fix this error?

Abhinav S

If (x2 - x1) is 0, the slope is infinity. Handle this case in code. Check and make sure (x2 - x1) is not 0 by a simple validation condition.

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