Creating Project Properties

How to use in practice

Creating project properties

When creating a project property you need to decide on:

1. The type of property you wish to create:
   • Standard – a typical property in p:IGI+ with one value per sample.
   • Gas – a gas property in p:IGI+ which might be measured as a volume, mol or mass fraction, or be of unknown fraction.
   • Molecular – a property typically measured by GC(MS) which can be measured as a height, area, concentration from height or concentration from area, or may be of unknown measurement.
2. The data type of the measurement, which can be Numerical or Text.
3. The short and long names for the property – short names are used in most places, for example on column headers in the spreadsheet, or as axis labels on graphs. Long names can be useful to help you find the property in the property search and can be more descriptive to help other users understand the meaning of the property you have created.
4. The analysis group to which the property should be added. By default we suggest adding new properties to the custom analysis group. This will make them easier to find, however if you want to add a new property, for example a new ratio to the Biomarker GCMSMS group then you can do that.
5. The unit group with which the numeric measurement is associated. By default we select the unitless unit group since we imagine you will often be creating new ratios, which are typically unitless, however you are free to use any of the unit groups available in p:IGI+; this will allow unit conversions on your new property within the unit group. Text properties will clearly not have units!
6. The default unit – by default we choose the base unit for the unit group you select. For example in the Unitless unit group the base unit is the Euclid (Euc) which is the natural non-dimensional unit, but you could choose to show the result by default in %.
7. The default number of decimal places to show in the page views. By default we set this to 1 decimal place, but you can adjust if you need to.
8. The default ratio with which to show the result. Set this to NoRatio if you don’t want to allow users to modify the ratio, but if the property you are creating is a ratio, then set this to the un—normalised (a/b) or normalised (a/(a+b)) ratio.
9. You can optionally add an equation, but more on that in the page on Creating project property equations.

Using project properties

Having created the property it will now appear like any other property in p:IGI+ and can be found using the standard property selector – just start typing the name of your new property and you can use this right across the system, in graphs, sample sets, pages, as an input to another equation for another new property. The only difference to the standard IGI supplied properties in p:IGI+ is that project properties only exist within the project you have created. At present the only way to remove a project property from p:IGI+ is to undo the creation (using Ctrl-z, or the undo icon); this completely removes the project property from the system.

Note that you should only set the ratio to something other than NoRatio if you want users to be able to change from normalised a/(a+b) to un-normalised a/b, and also the inverse of those: b/a and b/(a+b). 

Sharing project properties

The project property only exists within the project in which it was created. What if you want to share a graph (with overlays etc) that you created that help interpret the new project property. No problem, simple export the graph as a template, send this to your colleague and they can import the graph into their project. This will create your project property (and any associated equation) in their project, evaluate the equation in their project (this can cause the application to freeze for a short time on loading the template in big projects) and create your graph complete with overlay.

If you want to share a large number of project properties add them to a new page you have created and share the template for this page – this will add all project properties to another project. Be aware that creating project properties, particularly with equations, can be slow on large projects.

Editing / Deleting project properties

At present once a project property has been created there is no mechanism in place to either edit or delete the property. It will however only be present in the project you are working in (unless you decide to share / transfer that made project property to another project: See Sharing project properties above). 

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