Hi, all~

I have two seurat objects that I want to integrate.

> seu
An object of class Seurat 
22663 features across 66 samples within 1 assay 
Active assay: RNA (22663 features, 2000 variable features)
 2 dimensional reductions calculated: pca, umap

> mipsc
An object of class Seurat 
20391 features across 33966 samples within 1 assay 
Active assay: RNA (20391 features, 2000 variable features)
 2 dimensional reductions calculated: pca, umap

A problem arose when I ran 'FindIntegrationAnchors'.

I ran with the default setting it throwed an error complaining about 'cell number' and 'k.filter'.

So I lower the parameters and passed this step without error.

> anchors <- FindIntegrationAnchors(object.list = seu.list, 
                                   anchor.features = features,
                                   dims = 1:5, k.filter=1, k.score=1)
Scaling features for provided objects
  |++++++++++++++++++++++++++++++++++++++++++++++++++| 100% elapsed=03s  
Finding all pairwise anchors
  |                                                  | 0 % ~calculating  Running CCA
Merging objects
Finding neighborhoods
Finding anchors
    Found 330 anchors
Filtering anchors
    Retained 0 anchors
  |++++++++++++++++++++++++++++++++++++++++++++++++++| 100% elapsed=25s  

But soon, I found the retained anchor was 0, and of course the integration failed with another error.

> combined <- IntegrateData(anchorset = anchors, k.weight = 1)
Error in hclust(d = dist.mat) : 
  NA/NaN/Inf in foreign function call (arg 10)

Is this something to do with sample size difference between two data because it worked when I integrated using a much smaller dataset with 16 samples.

How can I solve this problem?

Thank you!