Preparing the Data

Using charts, especially scatter or bubble charts, can be quite complex. It is important that you plan the axis scaling, category group and series group expression in advance and know exactly how they will structure your data. Otherwise, you might get unexpected results and will not know which properties you must change in order to correct the result.

The data shown in the chart also depends on the report type and on whether the chart is placed in a composite group: In Single Injection reports, the entire template content is repeated for each single injection. It is therefore impossible to compare data from several injections in the same chart with a Single Injection report. In composite groups you can group, sort, and filter the data that will be available in a chart.

Read and understand the following before creating a chart:

• Which chart type suits your requirements?

  • If you want to label the x-axis with string values such as Sample 1, Sample 2, Sample 3, you will typically create a line chart or column chart.

  • If you want to label the x-axis with numeric values such as the retention time or the compound amount, you will typically create a scatter chart or bubble chart.

• How many data points do you want to show in the chart? For example, one for each sample, one for each compound, or one for each peak? Which expression can you use to distinguish the data? Use this expression for the category group.

• Do you need to distinguish the data aggregated by the category group? For example, the category group may distinguish the samples names, but you used two signals and want to display one data point per signal and sample name. Use the additional expression (in this example, the signal name) as a series group expression.

• Do you need to filter the data? For example, filter the data to show only specific compounds or only specific signals.

• Which values do you want to plot on the y-axis? These values must be numeric. We recommend using aggregating functions, as the category group may contain multiple values.

• For scatter charts and bubble charts: Which values do you want to plot on the x-axis? The x-values are typically numeric or date/time values. However, it is also possible to plot text values on the x-axis.

  For line and column charts, the category values are identical to the x-axis values. For scatter and bubble charts, the category group only has an impact on the amount of displayed data — the x-axis values are set separately and can differ from the category values.

• Do you need to sort the data? We recommend using the same expression for sorting and grouping the category group. In line and column charts, this sorts the labels on the x-axis. For scatter charts using lines, the line connects the data points in the order given by the category group.

• For bubble charts: Which value should influence the bubble size?