title: How fix character encoding in R plots?
body: <p>Recently, I installed R with anaconda. Apparently, everything works fine. However, when I plot something strange boxes with numbers appear instead of the letters and numbers.
  I think that I have a problem with character encoding.</p>
  <p>How can I fix this problem?
  I attach a sample plot with my problem.</p>
  <p><a href="https://i.stack.imgur.com/Se0b2.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/Se0b2.png" alt="enter image description here" /></a></p>
  <p>my sessionInfo() output is:</p>
  <pre><code>R version 3.6.1 (2019-07-05)
  
   Platform: x86_64-conda_cos6-linux-gnu (64-bit)
  
   Running under: Ubuntu 20.04.2 LTS
  
   Matrix products: default
   BLAS/LAPACK: /home/marco/anaconda3/envs/Rstudio/lib/R/lib/libRblas.so
   
   locale:
   [1] LC_CTYPE=es_MX.UTF-8       LC_NUMERIC=C               
   LC_TIME=es_MX.UTF-8        LC_COLLATE=es_MX.UTF-8    
  
   [5] LC_MONETARY=es_MX.UTF-8    LC_MESSAGES=es_MX.UTF-8   
   LC_PAPER=es_MX.UTF-8       LC_NAME=C                 
  
   [9] LC_ADDRESS=C               LC_TELEPHONE=C             
   LC_MEASUREMENT=es_MX.UTF-8 LC_IDENTIFICATION=C       
  
   attached base packages:
   [1] stats     graphics  grDevices utils     datasets  methods   base     
   
   other attached packages:
   [1] geometry_0.4.5               QuantumPhaseEstimation_0.1.0
  
   loaded via a namespace (and not attached):
   [1] compiler_3.6.1   rsconnect_0.8.17 tools_3.6.1      abind_1.4-5       yaml_2.2.1       Rcpp_1.0.6       pracma_2.3.3    
   [8] magic_1.5-9  
  </code></pre>
  <p>Also, I found that I can not install Cairo library</p>
  <pre><code>checking for ATS font support in Cairo... no
  configure: CAIRO_LIBS=-lcairo
  checking for library containing deflate... -lz
  checking whether Cairo programs can be compiled... configure: error: Cannot compile a simple Cairo program. See config.log for details.
  ERROR: configuration failed for package ‘Cairo’
  </code></pre>