How to calculate the correlation between the expression levels of two genes (features) ?

[Sunyp-IM]

Dear all,

In the Seurat package for scRNA-seq data analysis, there is a function called FeatureScatter, which can plot the scatter of the correlation between two features. I tried to make such a plot of two features in a dataset with the command:

FeatureScatter(object = obj, feature1 = 'Feature1', feature2 = 'Feature2')

and get the following image:

The Pearson correlation value of these two features is only 0.12. Are they not correlated? but it looks like they could be correlated.

Is there any standard for judging whether two variables are correlated or not in such a plot? Is the plot command not correct? Can the plot be improved and the calculated correlation value be corrected?

If FeatureScatter is not a suitable function to calculate the correlation, is there any other function that can do this?

Thank you!