WPS Spreadsheet: Create an Excel Chart with Upper, Optimal, and Lower Curves
Question details
The user needs to create one chart containing upper, optimal, and lower curves across the same set of x-values.
- Product
- WPS Spreadsheet
- Device & OS
- not provided
- Scenario
- The chart data has shared x-values and three corresponding value series that must be displayed as separate curves.
- Observed behavior
- The goal is to display the three value series correctly on an XY chart with the x-values used as the horizontal axis.
Arrange the data in four columns with headers: x-values, Lower, Optimal, and Upper. Make sure each curve has a value for every x-value and that the x-values are numeric if you want a true XY axis.
Create an XY Scatter chart for the three curves
Use this method when upper, optimal, and lower values share the same numeric x-values and need to appear as separate lines.
An XY Scatter chart treats the first column as numeric horizontal-axis values and the remaining columns as separate data series. Choose a smooth-line or straight-line version depending on whether the curves should be visually smoothed.
In WPS Spreadsheet, enter the shared x-values in column A, lower values in column B, optimal values in column C, and upper values in column D. Add clear headers in the first row.
Highlight the full table, including the headers and all four columns of data.
Open the Insert tab, choose Chart, select XY (Scatter), and then choose Scatter with Smooth Lines or Scatter with Straight Lines.
In the chart settings or data-selection panel, confirm that column A is assigned to the x-axis and that the Lower, Optimal, and Upper columns appear as three separate series.
Click each curve to adjust its line color, width, or marker style so the upper, optimal, and lower series are easy to distinguish.
Build multi-curve XY charts in WPS Spreadsheet
WPS Spreadsheet lets you organize shared x-values and multiple value series, then insert an XY Scatter chart with smooth or straight lines to compare upper, optimal, and lower curves.
- 1. Enter the curve data: Open WPS Spreadsheet and place x-values in the first column, followed by Lower, Optimal, and Upper values.
- 2. Select the source range: Highlight the headers and all rows containing the four data columns.
- 3. Insert the chart: Choose Insert > Chart, select XY (Scatter), and apply a smooth-line or straight-line chart style.
- 4. Check and format the series: Verify the first column is the x-axis and format the three curves with distinct colors or line styles.
Frequently Asked Questions
Why should I use an XY Scatter chart instead of a line chart?
An XY Scatter chart uses the first column as numeric x-values and positions points according to their actual spacing. Use it when the x-values are numeric and may not be evenly spaced.
How should I arrange the data for three curves?
Put x-values in the first column, followed by Lower, Optimal, and Upper values in columns B, C, and D. Include a header for each column and keep each row aligned to the same x-value.
How can I make the curves smooth?
After selecting the data, open Insert > Chart, choose XY (Scatter), and select the Scatter with Smooth Lines option. Use Straight Lines when the data should not be visually smoothed.
What should I check if the x-values appear as separate curves?
Open the chart's data-selection settings and confirm that the first column is assigned as the x-values for every series. The Lower, Optimal, and Upper columns should be separate y-value series.
