Analysing and charting trends and patterns in Volocity 4

As promised I’m continuing the theme from last time we spoke when I measured a batch of sequences together.  This created a measurement item containing the measured objects from all the timepoints of the selected sequences.

Here is the Raw view of that measurement item:

The 'Item Name' column lists the name of the image sequence, i.e. the item in the library, from which the measurements came.  Every measured object is represented as one row of measurements.

In the Analysis View the Analysis dialog is used to reorganize the data.  We can find the Analysis dialog by looking in the Analysis menu and choosing 'Analyze'.

The analysis dialog allows the reorganization of the data, to show up patterns or trends.

A simple starting point is to find out how many objects I’ve measured in each sequence.

By counting a property of each measured object, i.e. the ID and organizing the information by the item name, the analysis table now shows the total number of objects in each image sequence.

The table set up in the analysis view is plotted as a chart, I just need to click on the Chart tab to view it.

Now that’s got me into the swing of this dialog so I’m going to look at some different information that’s buried in the raw table.  I want to see how the mean intensity of these objects varies over time and I want to be able to compare the experiments on the same chart.

There is more than one object measured per timepoint in each of the image sequences, so the mean intensities of all the objects per timepoint need to be summarized in some way.  I am interested in a mean intensity for each timepoint so I obtain this by taking the mean of the individual means.  Then this is organized by timepoint to show time related changes.  To compare the values over the different image sequences I set the ‘Item Name’ as the Column.

As the ‘Item Name’ is the column heading in the table, each column will be a series on the chart, which I can view by clicking on the Chart tab.

There, I can clearly visualize not only the changes over time but also compare these between datasets.

While I’m here I’ll just try one more way of looking at this data.  If I need to look at more than two relationships I can use pages to add a third dimension to the table and chart.  In this example I could put the item name on separate pages, it might show this data in a whole new light.

I am already looking at the chart view but I can change the analysis from here, accessing from the drop-down menu from the Chart tab or using the ‘Spectacles’ button.

In the ‘Edit Analysis’ dialog, I’ve moved the ‘Item Name’ from the column setting, changing the column to ‘none’, and the page setting is now the ‘Item Name’. Now there is one chart for each image sequence and they’re arranged like pages, one behind the other.  I can see the pages using the pop-up at the top of the screen.

 

I hope this has been helpful, now I’m off to collect some more data to analyse in Volocity 4.

Wishing you all a happy and successful 2007!