Is there a way to create a LaTex half matrix in R?

Question

I am trying to use the xtable package to create a print-quality half matrix in R. I can create the full symetric matrix with no problem but when I extract only the lower triangle matrix, I get the error shown below.

library(Matrix)
datamat1<-tril(data1) #extract lower triangle
library(xtable)
options(xtable.floating = FALSE)
options(xtable.timestamp = "")
xtable(datamat1, digits = 3)

The error that I get is: "no applicable method for 'xtable' applied to an object of class "c('dtrMatrix', 'ddenseMatrix', 'triangularMatrix', 'dMatrix', 'denseMatrix', 'Matrix', 'xMatrix', 'mMatrix', 'Mnumeric', 'replValueSp')"

I know that converting the matrix to a half matrix also converts its class to dtrMatrix but there must be some way to export a lower triangle matrix in a publishable quality form. I have also tried using the 'zoo' package but without any luck. How can this be done.

user_496488 · Answer

Maybe keep the original matrix and just set the upper triangle to missing. Then you'll still have a regular matrix object that xtable can handle. The code below also shows a couple of other options besides xtable for printing. (If you need the dtrMatrix class object for further processing, you can of course just create that separately from the object created below for printing.)

---
title: "My Title"
output: pdf_document
---

```{r setup, include=FALSE}
knitr::opts_chunk$set(echo=FALSE)
library(tidyverse)
library(knitr)
library(gt)
library(xtable)
options(xtable.floating = FALSE)
options(xtable.comment = FALSE)
options(knitr.kable.NA="")
```

## Using `xtable`

```{r,  results="asis"}
set.seed(3)
m = matrix(1:16 + rnorm(16), nrow=4)
m[upper.tri(m)] = NA_real_

xtable(m, digits=3)
```

## Using `knitr::kable`

```{r}
colnames(m) = 1:ncol(m)
rownames(m) = 1:nrow(m)

kable(m, row.names=TRUE, digits=3)
```

## Using the `gt` package

```{r}
gt(as_tibble(m),
   rownames_to_stub=TRUE,
   digits) %>% 
  fmt_missing(columns=everything(), 
              missing_text="") %>% 
  fmt_number(columns=everything(), 
             decimals=3)
```

Is there a way to create a LaTex half matrix in R?

1 Answers