Large amounts of numerical data that need to be analyzed and processed are often much more convenient to represent in graphical form. The popular application for creating and editing Excel spreadsheets from Microsoft has a huge set of functions designed for this purpose. Moreover, practically anyone can master and apply them - from a schoolchild to a businessman or a scientist. It will take quite a bit of time to figure out how to build a graph in Excel.

## Plotting the ready data

Let us consider step by step plotting the plot using the ready data in Excel 2013. Suppose there is table of daily temperature values from September 1 to September 30, 2014 in three cities of Russia: Moscow, Magadan, Sochi. For clarity, it is required to present the data in a graphical form: so that the date is displayed on the abscissa axis, the temperature in^{0}C is displayed on the ordinate axis.

- We select four columns of the table containing the necessary information, together with the captions, then sequentially select in the main menu the items "Insert", "Recommended diagrams", "Insert graph" - as in the picture.
- The drop-down menu shows the possible types of graphs. We select "Graph with markers". After completing the above actions, the diagram shown in the figure is created on the current sheet.
- A legend is displayed under the graph - the labels of the data series (in this case, the names of the cities). For greater clarity, it is required to designate the axes and correctly title the diagram. Place the cursor on the default text “Chart name”, erase it and write in the selected field “Daytime temperature for September 2014 by cities of Russia”.
- To label the axes, click on the "Chart Elements" icon located next to the graph, check the "Axes Name" checkbox, as shown in the picture. Instead of the text that appears, enter "Date" and "Temperature, ⁰С".
- If you do everything correctly and slightly stretch the diagram in width, the finished graph will look like in the illustration. Now you can easily identify the days when it was warmer in Moscow than in Sochi, or colder than in Magadan!

## Plotting a function

Consider how to plot a graph in Excel, if you specify not numerical data, but a function. For example, there is a complex relationship y = f (x) = 2 (1-e^{-0.5x}cos (4x)), which you want to display in the diagram. To create a graph of a function in Excel, you first need to create a table containing x and y.

- Calculate the values of the function at x from 0 to 8 with a step of 0.25. In two horizontally adjacent cells, write down the names of the table columns. Below them, in the first column, enter 0 (the beginning of the range of x change), below - 0.25 (step), in the second - the formula for calculating y, starting with the "=" sign. You need to use the rules for writing mathematical functions in Excel and instead of an argument, specify the address of the cell containing its numerical value. As a result, the table should look like the one shown in the picture.
- Select the first two cells with x values, move the cursor to the lower right corner of the resulting frame, when the "" sign appears, use the left mouse button to stretch the area down - as in the picture... So the column is filled with values from 0 to 8. Similarly, copy the formula in the second column.
- Having received the data table, select it along with the headings, go to the menu items "Insert", "Recommended charts" and select a scatter chart with smooth lines (in the figure). If you want to display data labels, a similar type of graph with markers is used.
- Having signed the axes and the name, we get the following visual representation of the function under consideration:

As you can see, it is very easy to build a graph in Excel. In addition, the program has many tools to improve the perception of data: you can either use ready-made sets of styles and layouts for the design of charts, or independently customize the colors of the background, lines, text, grid spacing and other parameters. It is also very convenient that when the numerical values in the table change, the graph is automatically rebuilt.

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