How to import and compare curves

Introduction

This section describes how to import or copy curves from different runs into one chromatogram for comparison.

Commands to use

Two commands can be used to import curves from result files into one chromatogram:

  • File:Open to compare

    This is the preferred option if you want to automatically search result files that are stored in the same folder to locate all curves of a specified type, for example, all UV curves. This is especially useful for comparison of curves from scouting runs. Moreover, the imported curves can be automatically overlaid, stacked or presented as mirror images. See "How to use File:Open to compare" below.

  • File:Open:Curves

    This is the preferred option to import individual curves. See " How to use File:Open:Curves" below.

Note: Original curves are underlined in the chromatogram, imported and created curves are not underlined.

How to use File:Open to compare

The table below describes how to import curves to a chromatogram with the command File:Open to compare:

Step

Action

1

In the Evaluation module,

  • choose File:Open to compare:Curves

or

  • click the Open curves to compare toolbar button.

Result: The Open Curves to Compare dialog box opens.

2

  • Select the desired search criteria in the Folder, Result, Chromatogram and Curve name droplists of the Chromatogram selection section.

  • Click Search and a list of found curves will be displayed based on the selected search criteria.

Note: A new search can be performed with new search criteria without erasing curves located in the previous search.

  • Select the check boxes for the curves that you want to import. Click the Select All button if you want to import all the curves.

  • If you select the Store in new chromatogram option, the curves will be imported into a new chromatogram. This is recommended to keep the source chromatogram free of too many additional curves.

3

Select how to display the imported curves in the Curve options field and click OK. See the options below:

Overlay

The curves are presented overlaid on one another.

Stack

The curves are presented with a given offset Y-axis value so that the curves are stacked and distinct from one another.

Mirror

For comparison of two imported curves. One curve is inverted in the Y-axis and thus appears to mirror the other curve.

4

If you selected the Stack option in step 3, the Shift Curves by Offset dialog box is displayed:

  • You can set the Offset value to increase or decrease the offset distance between the curves.

  • Click OK.

Result: Depending on your previous choices, the imported curves are now displayed in the source chromatogram or in a newly created chromatogram.

Note: If curves with several different units have been selected, the curves with each different unit will be grouped together with separate offset from the other groups.

5

Change some comparison settings

  • Choose Edit:Chromatogram Layout to open the Chromatogram Layout dialog box.

  • Select or de-select the check boxes on the Curve tab to compare a different set of curves.

  • On the Y-Axis tab, the curves can be scaled

    individually

    all with the same scale (click the All with this unit button).

  • Click OK to display the curves.

6

If you stacked the curves and want to change the stack offset

  • choose Operations:Shift offset

  • type a new Offset value and click OK.

Note: The individual curves can also be moved (see How to stack and stretch curves).

How to use File:Open:Curves

The table below describes how to import individual curves into an active chromatogram with the File:Open:Curves command:

Step

Action

1

Make sure that the destination chromatogram for the imported curve(s) is active on the screen.

  • Select File:Open:Curves in the Evaluation module.

    Result: The Open Curves dialog box is displayed.

2

Select curves in the Open curves dialog box

  • Select the folder and the result file in the upper part of the dialog box.

  • Select a chromatogram on the Chromatogram drop-down list. Usually there is just one chromatogram.

Result: The available curves are listed on the Available list.

  • Click the check boxes on the Available list for the curves that you want to import and click the Select button.

Result: The selected curve(s) is displayed in the Selected curves list. To remove a curve from the Selected curves list, click the check box and then click the Remove button.

3

  • Repeat step 2 if you want to import curves from other chromatograms.

  • Click OK when you have selected the curves you want.

4

Change some comparison settings

  • Choose Edit:Chromatogram Layout to open the Chromatogram Layout dialog box.

  • Select or de-select the check boxes on the Curve tab to compare a different set of curves.

  • On the Y-Axis tab, the curves can be scaled

    individually

    all with the same scale (click the All with this unit button).

  • Click OK to display the curves.

How to copy curves into one chromatogram

A practical way to compare curves is to create a chromatogram and copy curves from different chromatograms into the new chromatogram. The comparisons are then performed in the new chromatogram.

The table below describes how to copy curves into a chromatogram:

Step

Action

1

Perform either A or B below:

A. Create a new chromatogram

  • Choose File:New:Chromatogram to create a new chromatogram.

B. Use the Temporary chromatogram

  • Choose Window:Temporary.

2

Open the source chromatogram(s)

Choose File:Open:Chromatogram to open the chromatogram(s) that contains the curves you want to copy.

Result: The Open Chromatogram dialog box opens.

3

  • Select the result file.

  • Click the check box for the source chromatogram in the Available list.

  • Click the Select button.

  • Click OK.

Result: The source chromatogram opens.

4

Copy the curves

  • Choose Edit:Copy:Curves.

Result: The Copy Curve dialog box is displayed.

5

  • Select the source chromatogram and a curve of interest in the Source Chromatogram field.

  • Select the target chromatogram (the one you created, or Temporary) in the Target Chromatogram field.

  • Click the Copy button.

  • Repeat this step for as many curves as you want, from the same or other chromatograms.

    Note: You can open more source chromatograms with the File:Open:Chromatogram command.

  • Click the Close button when you have copied all curves.

6

Change some comparison settings

  • Make sure the target chromatogram is open and that its window is active.

  • Choose Edit:Chromatogram Layout to display the Chromatogram Layout dialog box.

  • Select the curves that you want to view on the Curve tab and click OK.

  • The curves can be scaled individually or all with the same Y-axis scale. Use the All with this unit button on the Y-Axis tab to scale all curves with the same scale.

7

If you used the Temporary chromatogram

  • If you used the Temporary chromatogram you can perform evaluations in the Temporary chromatogram and transfer the final curves to other destination chromatograms.

  • All of the contents in the Temporary chromatogram can be removed with Edit:Clear Temporary Chromatogram.

Alternative way to copy curves

An alternative way to copy curves into one chromatogram is to

  • create a new chromatogram by copying an existing chromatogram and saving it under a new name

  • import more curves into the new chromatogram according to the instructions described above in this section.

2005-06-15