Use Graph analysis tools

Analyze data using the tools available on the graph page.

The following sections will demonstrate the various tools which can be used to analyze data on the graph page. For quicker navigation, use the Table of Contents at right to jump to a specific topic.

Change the scale and range

Use the following tools to adjust the scale and range of the graph display at any time.

Select and drag the x-axis to rescale the graph horizontally.
Select and drag the y-axis to rescale the graph vertically.
Select and drag the plot area to freely change the display's range while keeping the scale unchanged.
Select the Scale to Fit tool in the graph toolbar to automatically adjust the scale and range so that all of the displayed data fits on the graph display at once.

Scale to fit a region of data

Use the following steps to rescale and reposition the graph display so that a single section of data takes up the entirety of the view.

Select the Data Highlighter tool in the toolbar.
Select and drag over the region of data you wish to focus on to create a highlighter. All points in the highlighted region will be selected. If needed, you can select and drag the highlighter to reposition it, or select and drag the blue circles in the corners of the highlighter to change its dimensions.
Select the Scale to Fit tool to automatically adjust the scale and range so that only the highlighted data is visible.

Add or remove a y-axis

A new y-axis may be added to the graph display in either of the following ways:

Select the Add y-axis tool in the graph toolbar.
Select the original y-axis of the graph display, then select the Add y-axis button that appears next to the axis.

The second y-axis will be created on the right side of the graph area. Additional axes will alternate sides, with each new axis appearing farther from the graph than previously created ones. Up to four y-axes can be attached to the graph display at a time.

Note

While multiple y-axes are displayed and have measurements selected, the legend will update to include shortened names of each measurement at the top, with the points representing each measurement's runs in columns beneath the appropriate name, as shown below.

Legend with two measurements

To remove a y-axis (other than the original one, which cannot be deleted), select the axis and then select the Remove Axis button at the top.

Find the coordinates of a single point

Use the Coordinates tool to determine the coordinates of an individual data point.

Use the legend to make the run you wish to analyze visible.
Select the point you want to analyze. Several tools will become visible.
Select the Coordinates tool. This will create a data target over the chosen point, with a text box attached showing the point's coordinates.

You can also create a coordinate data target on the graph at any time by selecting the Coordinates tool in the graph toolbar. In this case, the data target will be created at the point closest to the center of the graph.

To change which point is selected, use the Previous Point and Next Point buttons to move left and right one point at a time. You can also select and drag the data target to a new data point to automatically move it to that point. You may delete the tool at any time by selecting the Delete button that appears when selecting the text box.

Compare the coordinates of multiple points

Use the Delta tool to compare coordinates within a run.

Follow the steps in the previous section to create a coordinate data target on the graph. Several tools will be visible next to the text box showing the coordinates of the selected point.
Move the data target to one of the points you wish to compare.
Select the Delta tool to add a second data target to the run.
Select and drag the second data target to the other point you wish to compare. Text boxes will automatically display the difference in the x and y coordinates between the two points.

Fit a curve to data

Use the Curve Fit tool to fit a curve to a segment of data.

Select the Data Highlighter tool in the graph toolbar.
Select and drag over the region of data you wish to focus on to create a highlighter. All points in the highlighted region will be selected. If needed, you can select and drag the highlighter to reposition it, or select and drag the blue circles in the corners of the highlighter to change its dimensions.
Select the Curve Fit tool from the graph toolbar, or the identical tool which appears when you select the highlighter.
From the list of fit options, select the option which best approximates the selected region of data.

A curve fit of the specified type will automatically be created on the graph, matching as closely as possible to the selected region of data. A text box connected to the fit line shows relevant values associated with the curve fit; for instance, if a linear fit is plotted, the box will show the slope and y-intercept of the created line, as shown below.

Note

A curve fit can still be created without highlighting a section of data by simply selecting the Curve Fit tool. In this case, the tool will create a curve fit for the entire run of data.

To delete a curve fit from the display, select the text box connected to the fit line and select the Delete button that appears.

Find the statistics of a range of data

Select the Data Highlighter tool in the Graph toolbar.
Select and drag over the region of data you wish to focus on to create a highlighter. All points in the highlighted region will be selected. If needed, you can select and drag the highlighter to reposition it, or select and drag the blue circles in the corners of the highlighter to change its dimensions.
Select the Statistics tool from the graph toolbar (or the identical tool which appears when you select the highlighter), then check the boxes next to the names of the statistics you wish to display.

A text box will then appear on the Graph display showing the selected statistics for the highlighted area. If no area of data is highlighted, the statistics text box will instead show the selected statistics for the entire run.

Statistics on the graph page

To delete a Statistics box from the display, select the box, then select the Delete button that appears.

Find the slope of a tangent line

Select the Slope tool from the graph toolbar. A data target with an attached tangent line and text box will automatically be created on the closest point to the center of the graph.
Select and drag the data target to the point you wish to find the tangent line for. The displayed tangent line will automatically adjust as it moves between points.

Note

You can also move the data target left or right by one point at a time by selecting the Previous Point or Next Point buttons above the text box.

The text box attached to the data target shows the coordinates of the selected point and the slope of the tangent line, as shown below.

Tangent line on the graph page

To delete a tangent line from the display, select the text box attached to that line, then select the Delete button that appears.

Add a note to a data point

Use the legend to make the run you wish to analyze visible.
Select the point you want to annotate to select it. Several tools will become visible.
Select the Add Note tool. An Edit Note window will automatically open.
Enter your desired text into the text box, then select OK.

Your note will now be displayed on the graph display, as shown below.

Custom note on graph

To edit your annotation after it is displayed, select the text box containing the annotation, then select the Edit Note tool that appears next to it. You can delete an annotation at any time by selecting the note and then selecting the Delete Note button.

Export graph data to an image

Generate an image file showing the current contents of the Graph display.

Select the Export Graph Image tool in the graph toolbar.
Using your device's file explorer, navigate to the location where you would like the image to be saved.
Enter a name for your image, then save the file.

Disable connecting lines

By default, connecting lines are shown between adjacent points on the graph display. These lines can be disabled if they are not ideal for your current experiment. To disable them, open the Preferences window from the Main Menu and disable the Show Connecting Lines preference. Connecting lines can be reenabled at any time.

Disable connecting lines

Note

The Show Connecting Lines preference is a global preference. Connecting line visibility cannot be toggled for individual runs of data.

Graph page without connecting lines

Show error bars on graph

Make error bars of a desired length visible on the graph display.

Select the Graph Settings tool in the graph toolbar.
Select the Error Bars box to open the Error Bars submenu.
Select the check box next to Show Error Bars to enable error bars and the other tools in the submenu.
Select the measurement for which you wish to adjust the error bar lengths from the Measurement Name box.
Choose an option for how the error bar lengths will be determined from the Error Bar Type box. Three options for this are available:
- Fixed Range: The length of each error bar is equal to a specific constant value.
- Percent of Value: The length of each error bar is a specific percentage of the data point value.
- Cross-run Average: Selecting this option creates a new "run" of data called Cross-run average, which can be plotted on the graph. Each value of this "run" consists of the average of the corresponding data points from a set of selected runs. Enabling this option also adds error bars to this "run", each with a length equal to the standard deviation of the points which were averaged to obtain the corresponding value.
Enter a value for the fixed length or percentage for the error bars above and the error bars below into the appropriate boxes. If you have selected "Cross-run Average" as your error bar type, instead select the box labeled Runs Averaged and check the box for each run you wish to be included in the Cross-run Average data set.

Tip

The product page for a sensor will usually list the expected accuracy of the sensor's measurements, which is usually an ideal length for the error bars. Select the link labeled "View sensor information" to open the product page for the selected measurement's sensor in your default web browser.
Select OK to close the Graph Settings menu and return to the graph page. The error bars (and, if applicable, the Cross-run Average data set) should now be visible on the graph.