Dear r-users,
I have this data:
structure(list(STUDENT_ID = structure(c(1L, 1L, 1L, 1L, 1L, 1L,
2L, 2L, 2L, 2L, 2L), .Label = c("AA15285", "AA15286"), class = "factor"),
COURSE_CODE = structure(c(1L, 2L, 5L, 6L, 7L, 8L, 2L, 3L,
4L, 5L, 6L), .Label = c("BAA1113", "BAA1322", "BAA2113",
"BAA2513", "BAA2713", "BAA2921", "BAA4273", "BAA4513"), class =
"factor"),
PO1M = c(155.7, 48.9, 83.2, NA, NA, NA, 48.05, 68.4, 41.65,
82.35, NA), PO1T = c(180, 70, 100, NA, NA, NA, 70, 100, 60,
100, NA), PO2M = c(NA, NA, NA, 37, NA, NA, NA, NA, NA, NA,
41), PO2T = c(NA, NA, NA, 50, NA, NA, NA, NA, NA, NA, 50),
X = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), X.1 = c(NA,
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA)), .Names = c("STUDENT_ID",
"COURSE_CODE", "PO1M", "PO1T", "PO2M", "PO2T", "X", "X.1"), class =
"data.frame", row.names = c(NA,
-11L))
I want to combine the same Student ID and add up all the values for PO1M,
PO1T,...,PO2T obtained by the same ID.
How do I do that?
Thank you for any help given
# load data
# Enter dataframe by hand
dat <- structure(list(STUDENT_ID = structure(c(1L, 1L, 1L, 1L, 1L, 1L,
2L, 2L, 2L, 2L, 2L), .Label = c("AA15285", "AA15286"), class = "factor"),
COURSE_CODE = structure(c(1L, 2L, 5L, 6L, 7L, 8L, 2L, 3L,
4L, 5L, 6L), .Label = c("BAA1113", "BAA1322", "BAA2113",
"BAA2513", "BAA2713", "BAA2921", "BAA4273", "BAA4513"), class =
"factor"),
PO1M = c(155.7, 48.9, 83.2, NA, NA, NA, 48.05, 68.4, 41.65,
82.35, NA), PO1T = c(180, 70, 100, NA, NA, NA, 70, 100, 60,
100, NA), PO2M = c(NA, NA, NA, 37, NA, NA, NA, NA, NA, NA,
41), PO2T = c(NA, NA, NA, 50, NA, NA, NA, NA, NA, NA, 50),
X = c(NA, NA, NA, NA, NA, NA, NA, NA, NA, NA, NA), X.1 = c(NA,
NA, NA, NA, NA, NA, NA, NA, NA, NA, NA)), .Names = c("STUDENT_ID",
"COURSE_CODE", "PO1M", "PO1T", "PO2M", "PO2T", "X", "X.1"), class =
"data.frame", row.names = c(NA,
-11L))
# Create sums by student ID
library(dplyr)
dat %>%
group_by(STUDENT_ID) %>%
summarize(sum.PO1M = sum(PO1M, na.rm = TRUE),
sum.PO1T = sum(PO1M, na.rm = TRUE),
sum.PO2M = sum(PO1M, na.rm = TRUE),
sum.PO2T = sum(PO1M, na.rm = TRUE))
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