Histogram Analysis

The ALiX Histogram Analysis window is mainly used when analyzing time traces but can also be used to analyze other plots (for instance, most graphs in the Burst Analysis page give access to an Histogram menu item, which will open the ALiX Histogram Analysis window).

Right-clicking on the legend of a plot in the Time Trace page offers the option to build an Histogram of that time trace. Once the bin size has been defined in the next pop-up window (see figure below), the resulting histogram will be computed and displayed in the ALiX Histogram Analysis window,

• Histogram Statistics

When an histogram is sent to the Histogram Window, basic statistics of the data array whose histogram is built are computed and stored in the Histogram Statistics array in ALiX. This allows using these quantities for scripted actions, such as for instance displaying them in the Monitored Variables Chart.

The computed histogram statistics are:

Mean

Standard Deviation

Variance

RMS

Median

Mode

Max Value

Min Value

# Elements

Count Rate (Hz)

P_any

P_a

The first element (Mean) can be accessed as Histogram Statistics[0], etc. The last three quantities are computed according to Eq. (4)-(6) in Ref. 12 listed in the Bibliography and only make sense for time traces of constant signal, binned with a time bin value of 1.

• Special contextual menu items

Since most plots in this window (except for fits) are histograms, some histogram-specific actions are offered by the right-click/contextual menu in the Graph legend.

• Rebin Histogram

This function will take the original data set and construct a new histogram with the new bin size defined by the user. The original histogram will be preserved.

• Invert Histogram

In some cases, a time trace is multiplied by -1 in order to avoid overlap with similar time traces. The resulting histogram will have negative bin locations. This function multiplies all bin location by -1 in order to create an histogram of the original value.