Interpolation is an essential tool for data analysts and researchers, allowing them to accurately predict values in a dataset by using existing data points. Excel is a powerful tool for interpolating data, as it provides users with the ability to quickly and intuitively calculate relevant values. By understanding the fundamentals of interpolation, Excel users can easily unlock the full potential of the program and maximize their data analysis capabilities.
In this blog post, we’ll cover the basics of interpolation in Excel and provide an easy-to-follow guide on how to successfully interpolate data in Excel. We’ll begin with a brief overview of what interpolation is and why it is necessary for data analysis. We’ll then move on to a step-by-step guide on how to interpolate data in Excel, covering everything from the basic formulas and functions to more advanced techniques. Finally, we’ll explore a few examples to help demonstrate how to interpolate in Excel, and discuss best practices for data analysis in
…
Linear Interpolation in Excel
- x is the input value.
- known_ys are the known y-values.
- known_xs are the known x-values.
How to perform linear interpolation in Excel with the mathematic formula
Using the mathematical formula y = y1 (x – x1) (y2 -y1) / (x2 – x1) is one method you can use to perform linear interpolation in Excel. Gather all the necessary information before beginning the calculation to ensure that it is accurate. Here are the steps for using the mathematical formula to perform linear interpolation in Excel:
1. Create a chart with your information
To organize your data and ensure accuracy in your calculation, the first step in using this method’s linear interpolation is to create a chart with all of your data. Label the first column of your chart “X” and the second column “Y” You can add your data points to the chart after labeling it.
2. Designate the cells where you want to input and receive values
The next step is to designate the cells where you want to plug in new data after charting the existing data. These cells can be marked with “value to interpolate” and “interpolated value.” This section of your spreadsheet is where you enter new values and get the formula’s results.
3. Input the formula
Click on your cell labeled “interpolated value. Navigate to the “formula bar” above the cell columns after clicking this cell. Put the formula y = y1 (x – x1) (y2 – y1) / (x2 – x1) in the formula bar.
4. Change the formula variable to the cell names
Once the formula has been written down, you can change the variable to the names of the cells that contain the necessary data. For instance, you can swap out the variables x1 and y1 with C4 and B4 if your coordinate’s x value is in cell C4 and y value is in cell B4. The formula can automatically adapt to any new information you enter in those cells by changing the variables in the formula to the locations of the cells.
Change the value of the formula variable y to the cell marked “value to interpolate” The formula will automatically return the calculated x value when you enter a number in that cell.
5. Test your formula
Once you’ve given each variable a cell location, test the formula to ensure it functions properly. To accomplish this, enter some coordinates that you are already familiar with. For instance, you can enter three into the cell marked “value to interpolate” if you are aware that the coordinate (4,3) is on your graph. ” The formula should return a value of four.
What is linear interpolation?
A mathematical technique called linear interpolation generates new data points based on previously collected data. In order to determine the relationship between the x and y coordinates on graphs and estimate new coordinates, the process examines known data points. For instance, linear interpolation might be used to determine the y coordinate for a given x value if you know three different coordinates on a line graph.
There are two primary methods for using linear interpolation in Excel. The first method involves using the fundamental linear interpolation mathematical formula. That formula is:
The equation y = y1 (x – x1) (y2 – y1) / (x2 – x1)
All of the values used in this formula—x1, x2, y1 and y2—are known. You can determine the other coordinate for a new value for y or x by inputting that value.
The FORECAST function, which can be used in Excel to perform linear interpolation, is =FORECAST(x,known_ys,known_xs). The elements of this function are:
How to perform linear interpolation in Excel with the FORECAST function
Instead of using the fundamental mathematical formula, you can use FORECAST to access Excel’s built-in functions. Here’s how to interpolate in Excel using the FORECAST function:
1. Chart your data points
The first step is to chart your data points. Label a column “X” and a column “Y” to reflect how the mathematical formula functions. After labeling, you can enter each piece of information you are already familiar with.
2. Designate your cells for the input and output formula
In the following step, you can label one cell “value to interpolate” and another “interpolated value.” These cells are where you can experiment with new coordinates and get the formula’s values. Putting these cells in a different column from the one from step one might be helpful.
3. Input your formula into the interpolated value cell
Click on the cell for the interpolated value after labeling the cells. Write out the FORECAST function in this cell’s “function” bar. The function is =FORECAST(x,known_ys,known_xs).
4. Assign the variables in the function to your cells
You can modify the variables after writing the FORECAST function to reflect the data in your cells. The location of the cell marked “value to interpolate” can be changed by changing the variable “x” there. “The known_x and known_y variables ought to represent the whole column of each coordinate”
For instance, you would change known_x to be B2:B9 if your coordinate chart has all the x coordinates in column B from lines two through nine. The function can read all of the x coordinates in that line thanks to this format. The entire function would look like this if your y coordinates are in column C from lines two through nine and your “value to interpolate” cell is cell D1.
=FORECAST(D1,C2:C9,B2:B9)
5. Test the formula
Once each step has been completed, test the formula to ensure that it is accurate. By including a few of your previously known coordinates, you can test the formula. You can enter two into the “value to interpolate” cell if you know that coordinate (2,5) is on your graph. The formula is valid if the interpolated value returns as five.
Please note that Indeed is not affiliated with any of the businesses mentioned in this article.
Linear Interpolation in MS Excel
FAQ
How do I interpolate between two numbers in Excel?
Excel’s XLOOKUP and FORECAST Functions Used in Combination to Interpolate Between Two Values Using the XLOOKUP function, you can extract the coordinates in a small range of the dataset that you want to interpolate within and interpolate a value there.
What does interpolation mean in Excel?
x is the known value, y is the unknown value, x1 and y1 are the coordinates that are below the known x value, and x2 and y2 are the coordinates that are above the x value. The formula is: y = y1 ((x – x1) / (x2 – x1))* (y2 – y1)
How do you do Vlookup and interpolate in Excel?
When the precise factor is absent from either a present value table or a future value table, interpolation is a method used to determine a present or future value factor. The assumption behind interpolation is that the difference between two values will change linearly and with a negligible margin of error.
