Reason for getting duplicate vertices in igraph plot

I am trying to make a plot using iGraph from a pivot table data in Excel. When I run my code, I notice I am getting duplicated vertex labels. I am attaching my code and sample data. Please help!

Data: https://drive.google.com/file/d/14Mfh41LJ7dN6QJR9wDlzG16XB93LB5Ne/view?usp=sharing

#read matrix csv file without heading
#call igraph library
#read as incidence matrix

library(igraph)
n <- graph_from_incidence_matrix(alzheimer)
pal <- rainbow(5, alpha=.5)

plot(n,
vertex.label = Data$X1,
vertex.size = 3,
label.dist = 100,
vertex.label.font = 3,
vertex.label.cex = 0.58,
vertex.color = pal,
edge.color = "gray",
vertex.label.dist = 1,
vertex.size = 10, asp = 9/16,
layout = layout.fruchterman.reingold
)

Solution

Your matrix was not symmetric and looks like an adjacency matrix. I made an edgelist out of them. The first column did not have a name. It will be called X1 by default in R.

library(tidyverse)
library(igraph)
#> 
#> Attaching package: 'igraph'
#> The following objects are masked from 'package:dplyr':
#> 
#>     as_data_frame, groups, union
#> The following objects are masked from 'package:purrr':
#> 
#>     compose, simplify
#> The following object is masked from 'package:tidyr':
#> 
#>     crossing
#> The following object is masked from 'package:tibble':
#> 
#>     as_data_frame
#> The following objects are masked from 'package:stats':
#> 
#>     decompose, spectrum
#> The following object is masked from 'package:base':
#> 
#>     union

alzheimer <- read_csv("~/Downloads/Data.csv")
#> Warning: Missing column names filled in: 'X1' [1]
#> 
#> ── Column specification ────────────────────────────────────────────────────────
#> cols(
#>   X1 = col_character(),
#>   a = col_logical(),
#>   b = col_double(),
#>   c = col_logical(),
#>   d = col_logical(),
#>   e = col_logical(),
#>   f = col_logical(),
#>   g = col_logical(),
#>   h = col_double(),
#>   i = col_logical(),
#>   j = col_logical(),
#>   k = col_double(),
#>   l = col_double()
#> )

n <-
  alzheimer %>%
  rename(from = X1) %>%
  pivot_longer(-from, names_to = "to") %>%
  filter(! is.na(value)) %>%
  select(from, to) %>%
  as.matrix() %>%
  graph_from_edgelist()

pal <- rainbow(5, alpha=.5)

plot(n,
     vertex.label = alzheimer$X1,
     vertex.size = 3,
     label.dist = 100,
     vertex.label.font = 3,
     vertex.label.cex = 0.58,
     vertex.color = pal,
     edge.color = "gray",
     vertex.label.dist = 1,
     vertex.size = 10, asp = 9/16,
     layout = layout.fruchterman.reingold
)

^{Created on 2021-10-05 by the reprex package (v2.0.1)}