Comments on: How to Normalize and Standardize Data in R for Great Heatmap Visualization https://www.datanovia.com/en/blog/how-to-normalize-and-standardize-data-in-r-for-great-heatmap-visualization/ Data Mining and Statistics for Decision Support Tue, 21 Apr 2020 06:54:28 +0000 hourly 1 https://wordpress.org/?v=6.8.2 By: kassambara https://www.datanovia.com/en/blog/how-to-normalize-and-standardize-data-in-r-for-great-heatmap-visualization/#comment-19676 Tue, 21 Apr 2020 06:54:28 +0000 https://www.datanovia.com/en/?p=15791#comment-19676 In reply to Jazmina.

Thank you Jazmina for your positive feedback, highly appreciated!

Standardization or Min-Max normalization?. There is no obvious answer to this question: it really depends on the application.

For example, in clustering analyses, standardization may be especially crucial in order to compare similarities between features based on certain distance measures.

Another example is the Principal Component Analysis, where we usually prefer standardization over Min-Max scaling, since we are interested in the components that maximize the variance.

In highthroughput gene expression data analyses,people tends to perform clustering on the standardized data (scale(log2(expression_data)))

A popular application of Min-Max scaling (or normalization) is image processing, where pixel intensities have to be normalized to fit within a certain range (i.e., 0 to 255 for the RGB color range). Also, typical neural network algorithm require data that on a 0-1 scale.

]]> By: Jazmina https://www.datanovia.com/en/blog/how-to-normalize-and-standardize-data-in-r-for-great-heatmap-visualization/#comment-19675 Tue, 21 Apr 2020 02:09:16 +0000 https://www.datanovia.com/en/?p=15791#comment-19675 Hi Kassambara,
I absolutely adore your articles. Thank you so so much for your amazing work. Super helpful!
I always had a question in regards scaling/normalizing data.
Depending on the method you use the clustering of the elements change. Sometimes it can change quite a lot. Then, how do you know which dendrogram is correct? Are all correct? Because, I am biologist and the interpretation of the data can vary substantially.
Again, thank you for your great contribution and help.
Jaz (Australia)

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