在Java中找到坡度的截距

Question

i want to find intercept of a series of value,since i have found the slope is there any way to find intercept value from slope or any other way to find intercept, this is my code,:

        double[] x_values = { 120,180,240 };
         double[] y_values = { l1,l2,l3};

                 if (x_values.length == y_values.length)
                 {
                 for (int i = 0; i < (x_values.length - 1); i++) {
                    double y_2 = y_values[i + 1];
                    double y_1 = y_values[i];

                    double delta_y = y_2 - y_1;

                    double x_2 = x_values[i + 1];
                    double x_1 = x_values[i];

                    double delta_x = x_2 - x_1;

                    slope += delta_y / delta_x;
                }
                 }
              double slope_val= slope / (x_values.length-1);

Answer 1

Fundamentally a line can be defined by two points. So if you're going to be finding the slope of a line, you can use two points to calculate it.

If you have more than two points, then you could use a more sophisticated extrapolation method. Two reasons for this: One, if your points aren't exactly co-linear than your algorithm is essentially just taking the average of the slope between consecutive point pairs. Two, even if you're points ARE co-linear there will probably be some numerical issues in the arithmetic that cause it to pretty much default to the first case. However, if you are in the second case then what you have is probably fine and you don't need to overcomplicate it.

Back directly to your question, you are finding the average slope between consecutive points. To find the intercept you're going to want to plug that slope into y=mx + b with one of your given points to find the b part of the equation. After that you're set to find the x-intercept or the y-intercept by setting either y=0 or x=0 , respectively, and solving.