# Review of Deep Work

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I recently read the book Deep Work by Carl Newport. In a short sentence, the book is anti-multitasking. More specifically, the book discusses the importance of focusing and concentrating in order to work deeply one topic and do it well.

I like the book, probably because it meets my preconceived notions about how to be effective. However, the book did provide new ideas for me so I decided to implement some of the book’s suggestions at work. Specifically, I scheduled my time and focused on one project at a time. By doing this, I got a great deal done. I suspect this was for 3 reasons:

1. First, I was being intentional about being productive;

I plan on adding this book to re-read every couple of years shelf and I highly recommend the book. I’ve also become aware of Carl’s blog because of the book and recommend that as well (Carl run a life hacks blog on working more efficiently). I particularly like his workflow re-engineering post. Maybe I’ll post an update of that works for me in a future post.

# tikz in LaTeX and Structural Equation Modeling

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During grad school, I attended an ESA Workshop on Structural Equation Modeling (SEM) let by Jim Grace. The approach allows for multivariate analysis with multiple predictors, multiple response variables, and latent variables. Up until now, my research never required using the method and I never bought the software he recommended at the time because the GUI program recommended by Grace was too expensive for my limited needs.

Recently, I had a need to use SEM at work. We had two response variables: environmental DNA (eDNA) and the ash-free dry weight of an aquatic organism (AFDW). Both were predicted by multiple environmental variables and AFDW predicted eDNA. A perfect problem for SEM.

To refresh myself of SEM, I revisited Grace’s work. I discovered that he maintains an excellent tutorial about SEM. The pages provide a nice introduction, as does his (slightly outdated) book, his classic book, and a recent Ecoshephere article.

However, I did not have a nice way to plot my results. I did not want to use a WYSIWYG tool like Inkscape or Power Point. But I remembered the tikz package in LaTeX. Here’s the figure I created:

Example SEM plot.

I created the figure using this LaTeX code:

 \documentclass{article}

 \usepackage[paperheight =11.3cm, paperwidth =9.5cm, margin = 0.1cm]{geometry} \usepackage{tikz} \usetikzlibrary{arrows} \usetikzlibrary{positioning} \begin{document} \pagenumbering{gobble} \begin{tikzpicture}[ -> , >=stealth',auto,node distance=3.5cm, thick,main node/.style={rectangle,draw, font=\sffamily}] \node[main node] (1) {Lake}; \node[main node] (2) [below of=1] {Depth}; \node[main node] (3) [below of=2] {Non-habitat}; \node[main node] (4) [below of=3] {Habitat}; \node[main node] (6) [below right of=2, align = center] {AFDW\\ $$r^2 = 0.223$$}; \node[main node] (7) [right of=6, align = center] {eDNA\\ $$r^2 = 0.384$$}; \path[every node/.style={font=\sffamily\small}] (1) edge node [above = 40pt] {\textbf{0.497}} (6) (2) edge node [left = 10pt] {\textbf{-0.370}} (6) (3) edge node [above] {0.094} (6) (4) edge node [left = 10pt] {0.116} (6) (1) edge[bend left] node [above = 10 pt] {\textbf{0.385}} (7) (2) edge[bend left] node [above = 5pt ] {0.197} (7) (3) edge[bend right] node [above = 0pt] {-0.298} (7) (4) edge[bend right] node [below = 5pt] {0.204} (7) (6) edge node [ ] {-0.180} (7); \end{tikzpicture} 

\end{document}