R Markdown Knitting header with JPG issue - r

Question

I am new to markdown and have to generate a weekly report with the proper header including a jpg image. I have the following yaml
---
title: "My Title"
author: "Author Name"
date: "`r Sys.Date()`"
header-includes:
- \usepackage{setspace}\doublespacing
- \usepackage{float}
- \usepackage{graphicx}
- \usepackage{fancyhdr}
- \pagestyle{fancy}
- \pretitle{\begin{center}
\includegraphics[width=2in]{picture.jpg}}
- \posttitle{\end{center}}
mainfont: Calibri
output:
pdf_document:
latex_engine: xelatex
---
Company policy states that all documents have to be in Calibri(I know) which was the main issue prior to this.
When I go to knit I get this error
Error in yaml::yaml.load(..., eval.expr = TRUE) :
Scanner error: while scanning a simple key at line 11, column 5 could not find expected ':' at line 12, column 5
Calls: <Anonymous> ... parse_yaml_front_matter -> yaml_load -> <Anonymous>
Execution halted
Any help on a resolution is much appreciated.

Answer 1

The first error Error in yaml::yaml.load(..., eval.expr = TRUE) : Scanner error: while scanning a simple key at line 11, column 5 could not find expected ':' at line 12, column 5 (as described in the question) originates from the fact that you are missing a - in line 11, so that line is considered as a key of YAML and since this key is missing a :, hence the error.
And after adding -, you are having another error ! Undefined control sequence. l.68 \pretitle {\begin{center} Error: LaTeX failed to compile (as said in the comment), because the command \pretitle is not recognised here. The command \pretitle (and also \postitle) comes from the latex package titling which is not specified here, hence the error.
Solution
Simply add the package titling using \usepackage in header-includes.
---
title: "My Title"
author: "Author Name"
date: "`r Sys.Date()`"
header-includes:
- \usepackage{setspace}\doublespacing
- \usepackage{float}
- \usepackage{graphicx}
- \usepackage{fancyhdr}
- \usepackage{titling}
- \pagestyle{fancy}
- \pretitle{\begin{center}
- \includegraphics[width=2in]{picture.jpg}}}
- \posttitle{\end{center}}
mainfont: Calibri
output:
pdf_document:
latex_engine: xelatex
---