Do a correlation test between two datasets of different sizes (one has 24, the other one 25 values) in R

Question

when doing a correlation test in R (doesnt matter if its spearman, pearson or anything else) it always gives me the following error:

Fehler in cor.test.default(young1$Viral.load, old1$Viral.load, method = "spearman") : 
  'x' und 'y' müssen dieselbe Länge haben

Its german but it tells me that x and y must be of the same lenght. This confuses me because my assignment is to test for correlation, how tf am i supposed to do it now?

I tried :

correlation_drug1 <- cor.test(
    young1$Viral.load,
    old1$Viral.load,
    method = "spearman"
  )

and i was expecting it to work :(

Answer 1

for correlation tests, the data from two groups must be of same size, which is one of the assumptions of correlation tests.

Can you make sure you include complete data set and exclude invalid data?