I have a data frame in R that I want to analyse. I want to know how many specific numbers are in a data frame column. for example, I want to know the frequency of number 0.9998558 by using

sum(deviation_multiple_regression_3cell_types_all_spots_all_intersection_genes_exclude_50_10dec_rowSums_not_0_for_moran_scaled[,3]== 0.9998558)

However, it seems that the decimal shown is not the actual one (it must be 0.9998558xxxxx) since the result I got from using the above command is 0 (the correct one should be 3468). How can I access that number without knowing the exact decimal numbers so that I get the correct answer? Please see the screenshot below.

CodePudding user response：

The code below gives the number of occurrences in the column.

x <- 0.9998558
length(which(df$a==x))

CodePudding user response：

If you are looking for numbers stating with 0.9998558, I think you can do it in two different ways: working with data as numeric or as character. Let x be your variable:

Data as character

This way counts exactly what you are looking for

  sum(substr(as.character(x),1,9)=="0.9998558")

Data as numeric

This will include all the values with a difference with the reference value lower than 1e-7; this may include values not starting exactly with 0.9998558

  sum(abs(x-0.9998558)<1e-7)

You can also "truncate" the numbers in your vector and compare them with the number you want. Here, we write 10^7 because 7 is the number of decimals you want to compare.

sum(trunc(x*10^7)/10^7)==0.9998558)