根据另外两列创建试用列

Question

我能否基于此示例数据中的 subject 和 new_stimulus 列创建试用列？对于每个受试者，试验列将是他们有多少 'CS+' 和 'CS-'。

这是我的预期结果

（计算每个科目有多少 CS+ 和 CS- 并创建一个名为“试验”的列）

数据样本

data <- structure(list(subject = c("subject1", "subject1", "subject1", 
"subject2", "subject2", "subject2"), new_stimulus = c("CS-", 
"CS-", "CS+", "CS-", "CS-", "CS+")), row.names = c(NA, -6L), groups = structure(list(
    subject = c("subject1", "subject1", "subject2", "subject2"
    ), new_stimulus = c("CS-", "CS+", "CS-", "CS+"), .rows = structure(list(
        1:2, 3L, 4:5, 6L), ptype = integer(0), class = c("vctrs_list_of", 
    "vctrs_vctr", "list"))), row.names = c(NA, 4L), class = c("tbl_df", 
"tbl", "data.frame"), .drop = TRUE), class = c("grouped_df", 
"tbl_df", "tbl", "data.frame"))