Error: Column must be length 1 (a summary value), not 3 - r

Question

I have been having this problem and I cannot see what is the error. I have seen in other posts that others run into similar problems but none of the answers helps me understand what is the problem in my df.
I have the following df.
structure(list(Position = c(2049L, 165L, 1949L, 1491L, 1550L,
118L, 164L, 2049L, 165L, 1654L, 1766L, 1949L, 891L, 1491L, 1550L,
118L, 26L, 1766L, 1949L, 1491L, 1550L, 775L, 775L, 2049L, 165L,
1949L, 100L, 891L, 1491L, 1550L, 118L, 2049L, 165L, 634L, 1654L,
1949L, 100L, 891L, 1491L, 1550L, 118L, 26L, 742L, 100L, 1491L,
26L, 934L, 2049L, 165L, 634L, 1654L, 1949L, 891L, 7L, 1491L,
1550L, 118L, 26L, 742L, 164L, 934L, 2049L, 165L, 634L, 1654L,
1949L, 891L, 1949L, 7L, 1491L, 1550L, 118L, 26L, 742L, 164L,
934L, 2049L, 165L, 634L, 1654L, 1949L, 891L, 1949L, 7L, 1491L,
1550L, 118L, 26L, 742L, 934L, 2049L, 634L, 1949L, 100L, 891L,
1491L, 1550L, 118L, 26L, 742L, 934L, 2049L, 165L, 634L, 1949L,
100L, 891L, 1491L, 1550L, 118L, 26L, 742L, 934L, 2049L, 165L,
634L, 1654L, 1949L, 100L, 891L, 1491L, 1550L, 118L, 26L), Freq = c(0.067775,
0.033818, 0.03713, 0.048681, 0.099359, 0.023134, 0.025509, 0.188382,
0.067254, 0.045069, 0.023901, 0.092243, 0.046262, 0.075173, 0.221062,
0.0453, 0.022977, 0.027029, 0.028103, 0.052525, 0.112694, 0.048416,
0.048416, 0.112287, 0.029838, 0.044125, 0.023682, 0.02216, 0.051012,
0.155826, 0.039267, 0.078809, 0.029748, 0.022649, 0.021723, 0.057707,
0.024649, 0.023452, 0.06311, 0.105783, 0.032374, 0.023256, 0.020603,
0.053108, 0.047462, 0.020855, 0.039699, 0.149017, 0.059824, 0.055523,
0.030769, 0.091152, 0.029758, 0.028419, 0.127958, 0.213058, 0.062456,
0.024057, 0.021788, 0.029876, 0.085926, 0.232437, 0.055515, 0.071291,
0.026907, 0.085498, 0.084755, 0.020671, 0.026855, 0.207147, 0.133883,
0.038205, 0.05364, 0.0545, 0.028277, 0.047527, 0.277206, 0.061392,
0.043723, 0.027954, 0.130286, 0.05974, 0.020242, 0.042113, 0.139535,
0.161506, 0.046344, 0.04523, 0.043121, 0.02829, 0.038206, 0.030329,
0.030099, 0.02749, 0.023106, 0.094997, 0.054054, 0.037677, 0.038858,
0.032011, 0.039477, 0.042833, 0.021013, 0.041847, 0.049717, 0.043711,
0.029877, 0.080454, 0.068994, 0.042294, 0.029737, 0.028315, 0.024932,
0.056885, 0.039822, 0.020568, 0.025144, 0.070069, 0.065646, 0.025337,
0.081133, 0.200188, 0.037447, 0.020874)), row.names = c(NA, -124L
), class = c("grouped_df", "tbl_df", "tbl", "data.frame"), groups = structure(list(
Position = c(7L, 26L, 100L, 118L, 164L, 165L, 634L, 742L,
775L, 891L, 934L, 1491L, 1550L, 1654L, 1766L, 1949L, 2049L
), .rows = list(c(54L, 69L, 84L), c(17L, 42L, 46L, 58L, 73L,
88L, 99L, 111L, 124L), c(27L, 37L, 44L, 94L, 106L, 119L),
c(6L, 16L, 31L, 41L, 57L, 72L, 87L, 98L, 110L, 123L),
c(7L, 60L, 75L), c(2L, 9L, 25L, 33L, 49L, 63L, 78L, 103L,
115L), c(34L, 50L, 64L, 79L, 92L, 104L, 116L), c(43L,
59L, 74L, 89L, 100L, 112L), 22:23, c(13L, 28L, 38L, 53L,
67L, 82L, 95L, 107L, 120L), c(47L, 61L, 76L, 90L, 101L,
113L), c(4L, 14L, 20L, 29L, 39L, 45L, 55L, 70L, 85L,
96L, 108L, 121L), c(5L, 15L, 21L, 30L, 40L, 56L, 71L,
86L, 97L, 109L, 122L), c(10L, 35L, 51L, 65L, 80L, 117L
), c(11L, 18L), c(3L, 12L, 19L, 26L, 36L, 52L, 66L, 68L,
81L, 83L, 93L, 105L, 118L), c(1L, 8L, 24L, 32L, 48L,
62L, 77L, 91L, 102L, 114L))), row.names = c(NA, -17L), class = c("tbl_df",
"tbl", "data.frame")))
I run the following code:
X.3 %>%
group_by(Position) %>%
summarize(Freq, Sum = Sum(Freq))
and I get the message: Error: Column Freq must be length 1 (a summary value), not 3
Why is this taking it with a value of 3? Sorry, may be some very basics stuff but I cannot solve it.
many thanks in advance.

Answer 1

If we use the new version of dplyr (version >= 1.0), it won't show that error because summarise can return more than one row
library(dplyr)
df %>%
group_by(Position) %>%
summarize(Freq, Sum = sum(Freq), .groups = 'drop')
-output
# A tibble: 124 x 3
Position Freq Sum
<int> <dbl> <dbl>
1 7 0.0284 0.0974
2 7 0.0269 0.0974
3 7 0.0421 0.0974
4 26 0.0230 0.279
5 26 0.0233 0.279
6 26 0.0209 0.279
7 26 0.0241 0.279
8 26 0.0536 0.279
9 26 0.0452 0.279
10 26 0.0389 0.279
# … with 114 more rows
Or another option is to create a list column and then unnest
library(tidyr)
df %>%
group_by(Position) %>%
summarize(Sum = sum(Freq), Freq = list(Freq)) %>%
unnest(c(Freq))