XLSTAT: Dynamic Histograms in Excel

 

Case 1

Dataset for Example

In this case, we imagine we have used two techniques to make a measurement. The data have been recorded in two different columns, and the two samples are independent because measures were not taken simultaneously.

 

Setting up

• Open XLSTAT.

• Click on the Visualizing data  menu and select the Histograms feature:

• Once you've clicked on the button, the dialog box appears.

• In the General tab, select the A and B columns in the Data field.

 

• In the Options tab we set the number of intervals for the histogram to 5. 

 

• In the Chart tab, choose to display a normal distribution curve fitted to the data, as we think the data should follow a normal distribution. 

 

• Click on the OK button to launch the computations.

• The results are displayed on a new Excel sheet.

 

Interpreting the Results

The first chart is a dynamic histogram. The list box at the top left of the chart allows you to choose which sample is displayed in the front.

 
The second chart allows to see the two samples and the corresponding fitted normal distributions.

Case 2

Dataset for Example

In this case, we imagine we have used a technique to make a measurement on a series of products. The measures have been recorded by two different operators (0 / 1). In an exploratory phase, we want to visually investigate whether they are different or not.

 

Setting up

• Open XLSTAT.

• Click on the Visualizing data  menu and select the Histograms feature:

• Once you've clicked on the button, the dialog box appears.

In the General tab:

• Select the column A in the Data field. 

• Select column C in Subsamples field. The information telling which operator made the measurement is recorded in column C.

  
In the Options tab:

• Set the number of intervals for the histogram to 5.

• Activate the Compare the subsamples option to compare the samples .

• Activate the Compare to the total sample option to see the distribution of the data taken all together.

  

In the Charts tab:

• Choose to display a normal distribution curve fitted to the data, as we think the data should follow a normal distribution. 

 

• Click on the OK button to launch the computations.

• The results are displayed on a new Excel sheet.

 

Interpreting the Results

The first chart is a dynamic histogram. The list box at the top left of the chart allows you to choose which subsample is displayed in the front. X1 corresponds to the merged data. In the image above, it is in the background, hidden by the two subsamples.

The second chart allows to see the two sub-samples corresponding to each operator and the normal distribution fitted to the total sample (it would be displayed for each sub-sample if the Compare to the total option had not been activated).