Imputing missing data with the NIPALS method with XLSTAT

Goal of this tutorial

The goal of this tutorial is to impute missing value in a dataset using the NIPALS algorithm.

Principle of the NIPALS approach for completing missing data

The NIPALS method is a method presented by H. Wold (1973) to allow principal component analysis with missing values. The NIPALS algorithm is applied on the dataset and the obtained PCA model is used to predict the missing values.

Dataset for completing missing data

An Excel sheet with both the data and the results can be downloaded by clicking here. In this tutorial we show how to complete missing values. .

The dataset contains six variables and six observations with six missing values.

Imputing missing value

After opening XLSTAT, select the XLSTAT / Preparing data / Missing data command, or click on the corresponding button of the Preparing datamenu (see below).

menu missing 

Once you've clicked on the relevant button, the dialog box appears. Select the data you want to complete in the data field (in our case the table with missing values). The type of data is quantitative. Select the method, we use NIPALS.

Activate the option for observation labels and select the name of the cars.

 dialog box missing

Once you have clicked on the OK button, the results are displayed on a new sheet.

Results of the imputation process

Descriptive statistics tables are displayed (one table before and a second one after imputation).

 descriptive statistics missing

 descriptive statistics missing

Then the completed data is displayed.

 completed data

We can see in bold the completed values. We can compare these values to the real value available in this dataset:

real data

We can see that imputed missing values are very close to the real values. For example for the displacement of Honda Civic, the real value is 1396 and the imputed value is 1365.236. If we had used a mean imputation method, the imputed value would have been 1781.4 which is very far from the value obtained with NIPALS.

Click here for other tutorials.

About KCS

Kovach Computing Services (KCS) was founded in 1993 by Dr. Warren Kovach. The company specializes in the development and marketing of inexpensive and easy-to-use statistical software for scientists, as well as in data analysis consulting.

Mailing list Join our mailing list

Home | Order | MVSP | Oriana | XLStat
QDA Miner | Accent Composer | Stats Books
Stats Links | Anglesey

Share: FacebookFacebook TwitterTwitter RedditReddit
Del.icio.usDel.icio.us Stumble UponStumble Upon

 

Like us on Facebook

Get in Touch

  • Email:
    sales@kovcomp.com
  • Address:
    85 Nant y Felin
    Pentraeth, Isle of Anglesey
    LL75 8UY
    United Kingdom
  • Phone:
    (UK): 01248-450414
    (Intl.): +44-1248-450414