I have one graph in x and y coordinate axis and I want to know equation of this graph. Is there any method?

Question

I am able to find out coordinate in X & Y axis. These coordinate graph look like a curve. This equation required to feed the formula in MS excel format for calculate automate any calculation. So that, no need to refer graph.

Answer 1

Do a reversal in steps.

Answer 2

Equations are determined by curve-fitting formulas. The most common method is called linear regression. This is used if the graph is a straight line, and Excel will compute that. For other curves, linear regression can be used by coordinate transformation. For example, if the graph looks like an exponential curve, you can use the logarithm of the x-axis number in a linear regresstion algorithm. More general curve-fitting formulas use poynomials of varying degrees to get the best fit.

Answer 3

As far as I know there is no way to find the exact equation; however there is one practical method:

Select several points on the graph so you will have several pairs of (X,Y). Then with a regression method find the equation of a curve that passes through the points. More points you select more accurate will be the result.

Moreover, you can enter the coordinates to excel and the software can perform regression for you (look in its help for regression).

Answer 4

MS Excel has several functions you can use to find an equation that is the best fit for the data you have. LINEST and TREND are two such functions. LINEST can be used to find equations that will fit data for multiple independent variables and one dependent variable; like y = ax + bz + c; where x and z are independent variables and y is the dependent one. c is a constant.

For the above equation, you'd need three columns of data: one for the y data, one for x, and one for z. For example, y might be number of houses sold each month, x might be loan interest rates, and z might be average cost of homes. Plugging the three columns of data into LINEST, you can find what a, b, and c are and, consequently, what the specific equation for your data is.

LINEST can be found in INSERT/FUNCTION on Excel's toolbar; where you scroll down the FUNCTION popup to find and select LINEST. The good news about the FUNCTION inserts is that each function, like LINEST and TREND, comes with an excellent tutorial that not only explains how to use each function, but also provides excellent examples on how to use it. You can actually copy and paste each example into an Excel worksheet and play around with it until you get the right answers the example provides. Great learning tool.

Regression, which is what LINEST and TREND do, is a very powerful tool for finding specific equations based on data points (the columns of data). Data points are what one graphs on graph paper. For a simple x, y graph, you'd have an equation like y = ax+ b; where x is the independent and y the dependent variable, with b as the constant. You might also have y = ax^2 + bx + c; where y is dependent and x is still independent, c is now the constant.

Answer 5

Collects points on the graph, Use Regression formula(Procedure) to get the equation of the graph.

Answer 6

First, make a chart, 2 colums of, arbitrarily, 10 rows. Lable one column 'x' and the different 'y'. %. arbitrary values for the fashion of x, say -10 to 10 in increments of a million. positioned those numbers interior the 'x' column. for each value of x, calculate y and positioned the leads to column y. once you have executed the chart, on slightly graphing paper, plot each and each row (x, y) value with a dot. Then, connect the dots. it would be lots much less perplexing to describe this in case you coated the equations.

Answer 7

You will need to work with the co-ordinates of points (x,y) on the curve that you have already and work out the relationship between points from that.