I tried drawing this diagram in latex but I'm having trouble with the arrows

Question

This is the diagram I want to draw

This is what I've been able to do

Here's my code

\usepackage{tikz}
\usetikzlibrary{shapes, arrows.meta, positioning}
\begin{document}
\begin{figure}[!ht]
 \centering
 \hspace*{-20pt} 
\begin{tikzpicture}
\node[draw,
       minimum width=1.5cm,
       minimum height=1.5cm] (blockI) at (0,0) {\textbf{I}};
\node[draw,
       minimum width=1.5cm,
       minimum height=1.5cm] (blockL) at (0,-4) {\textbf{L}};
\node[draw,
       minimum width=1.5cm, 
       minimum height=1.5cm] (blockR) at (3,-4) {\textbf{R}};
\node[draw,
       minimum width=1.5cm, 
       minimum height=1.5cm] (blockC) at (6,-4) {\textbf{C}};
   \node[draw,
       minimum width=1.5cm, 
       minimum height=1.5cm] (blockT) at (-3,-4) {\textbf{T}};
   \node[draw,
       minimum width=1.5cm, 
       minimum height=1.5cm] (blockS) at (-6,-4) {\textbf{S}};
   \node[draw,
       minimum width=1.5cm, 
       minimum height=1.5cm] (blockA) at (0,-8) {\textbf{A}};
%%arrows%%
\draw[stealth-] (blockI) -- (blockS);
\draw[stealth-] (blockI) -- (blockT);
\draw[stealth-] (blockI) -- (blockR);
\draw[stealth-] (blockI) -- (blockC);
\draw[stealth-] (blockR) -- (blockI);
\draw[stealth-] (blockC) -- (blockI);
\draw[stealth-] (blockL) -- (blockS);
\draw[stealth-] (blockT) -- (blockL);
\draw[stealth-] (blockL) -- (blockT);
\draw[stealth-] (blockC) -- (blockL);
\draw[stealth-] (blockL) -- (blockR);
\draw[stealth-] (blockA) -- (blockS);
\draw[stealth-] (blockA) -- (blockT);
\draw[stealth-] (blockA) -- (blockL);
\draw[stealth-] (blockA) -- (blockR);
\draw[stealth-] (blockA) -- (blockC);
\draw[stealth-] (blockT) -- (blockA);
\draw[stealth-] (blockC) -- (blockA);
\end{tikzpicture}
\end{figure}
\end{document}

If I could get help with the arrows, I think I can do the labels on my own. Thanks

EDIT

With all the help, I've been able to arrive at this, thanks to all the helpers

But my code is having a lot of errors that I do not know how to correct on overleaf. Here's my code

\usepackage{tikz}
\usetikzlibrary{shapes, arrows.meta, positioning}
\begin{document}
\centering
\begin{tikzpicture}
\node[draw,
    minimum width=1.5cm,
    minimum height=1.5cm] (blockI) at (0,0) {\huge I};

\node[draw,
    minimum width=1.5cm,
    minimum height=1.5cm] (blockL) at (0,-4.5) {\huge L};

\node[draw,
    minimum width=1.5cm, 
    minimum height=1.5cm] (blockR) at (3.3,-4.5) {\huge R};

\node[draw,
    minimum width=1.5cm, 
    minimum height=1.5cm] (blockC) at (7,-3.5) {\huge C};
\node[draw,
    minimum width=1.5cm, 
    minimum height=1.5cm] (blockT) at (-3.3,-4.5) {\huge T};
\node[draw,
    minimum width=1.5cm, 
    minimum height=1.5cm] (blockS) at (-7,-3.5) {\huge S};
\node[draw,
    minimum width=1.5cm, 
    minimum height=1.5cm] (blockA) at (0,-8) {\huge A};

\draw[Stealth-] (blockI) -- (blockS)
    node[pos=0.5,above,rotate=25] {$\lambda__H$};
\draw[Stealth-] (blockI) -- (blockT)
    node[pos=0.5,above,rotate=57] {$\alpha \lambda_H$};
\draw[Stealth-] (blockI.south) -- (blockR.north west)
    node[pos=0.5,below,rotate=-50] {$\varphi \lambda__H $};
\draw[Stealth-] ([yshift=3mm]blockI.east) -- ([xshift=-2mm]blockC.north)
    node[pos=0.5,above,rotate=-20] {$\gamma__T$};
\draw[Stealth-] (blockR.north) -- (blockI)
    node[pos=0.5,above,rotate=-45] {$\gamma__I$};
\draw[Stealth-] (blockC) -- (blockI)
    node[pos=0.5,below,rotate=-25] {$\eta__1 \lambda_H$};
\draw[Stealth-, rotate=0] ([xshift=-4mm]blockL) |- ([yshift=5mm]blockS)
    node[pos=0.85,above] {$\theta \lambda__T $};
\draw[Stealth-] ([yshift=3mm]blockT.south east) -- ([yshift=3mm]blockL.south west)
    node[pos=0.5,below] {$\gamma__L$};
\draw[Stealth-] (blockL) -- (blockT)
    node[pos=0.50,above,rotate=0] {$\omega \sigma \lambda__T$};
\draw[-Stealth, rotate=0] ([xshift=4mm]blockL) |- ([yshift=5mm]blockC)
    node[pos=0.85,above,rotate=0] {$\lambda__H$};
\draw[Stealth-] (blockL) -- (blockR)
    node[pos=0.5,above] {$\rho \psi \lambda__T$};



\draw[Stealth-] ([yshift=-12mm]blockA.north west) -- ([xshift=-2mm]blockS.south east)
    node[pos=0.7,below,rotate=-37] {$(1-\theta) \lambda__T$}; 
\draw[Stealth-] (blockA) -- (blockL)
    node[pos=0.5,left] {$\xi$};
\draw[Stealth-] (blockA) -- (blockR)
    node[pos=0.5,above,rotate=49] {$(1-\rho) \psi \lambda__T$};
\draw[Stealth-] ([xshift=2mm]blockC.south) -- ([yshift=-4mm]blockA.east)
    node[pos=0.5,below,rotate=35] {$\eta__2 \lambda__H$}; 
\draw[Stealth-] (blockA.east) -- (blockC.south west)
    node[pos=0.5,above,rotate=35] {$\gamma__H$};
\draw[Stealth-] (blockA.west) -- (blockT.south)
    node[pos=0.7,below,rotate=-45] {$(1-\omega) \sigma \lambda_T $}; 
\draw[Stealth-] (blockT.south east) -- (blockA.north west)
    node[pos=0.5,above,rotate=-45] {$\gamma__A$};

%%single-node arrows%%
\draw [-Stealth](blockS) -- (-7,-5.5)
    node[pos=0.5,left]{$\mu__H$};
\draw [Stealth-](blockS) -- (-7,-1.5)
    node[pos=0.5,left]{$\lambda__H$};
\draw [-Stealth](blockI) -- (0,2)
    node[pos=0.5,left]{$\delta_I+\mu__H$};
\draw [-Stealth](blockL) -- (0,-2.5)
    node[pos=0.8,left]{$\mu__H$};
\draw [-Stealth](blockR) -- (5.3,-4.5)
    node[pos=0.6,above]{$\mu__H$};
\draw [-Stealth](blockC) -- (7,-1.5)
    node[pos=0.5,right]{$\delta_C+\mu__H$};
\draw [-Stealth](blockA) -- (0,-10)
    node[pos=0.5,left]{$\delta_A+\mu__H$};



\end{tikzpicture}


\end{document}

Please help me remove the errors.

You can use \draw[Stealth-, rotate=20] (blockL) |- (blockS); for the arrows with a kink in it. (Note the usage of capital S in Stealth which actually uses the arrows.meta arrow tips.) The other ones aren't that easy but you can always use the named (or the angle) anchors: \draw[Stealth-] ([yshift=-2mm]blockA.north west) -- ([xshift=-2mm]blockT.south east); \draw[Stealth-] ([xshift=2mm]blockT.90) -- ([yshift=2mm]blockA.180);. They aren't perfectly parallel, that needs more math. — Qrrbrbirlbel, Dec 26 '22 at 15:57
Thanks a lot! This has helped tremendously. Now the problem I have is creating those arrows that do not terminate at a node. Please how do I go about that? @Qrrbrbirlbel — Nathaniel Ekong, Dec 26 '22 at 17:50
Just use ordinary coordinates (x,y), ++(x,y), polar ++(angle: r) or calc tikzlibrary constructions ($(blockA)!0.5!(blockB)$). — John Kormylo, Dec 26 '22 at 21:14
You actually now have a new question, isn't it? it will be fer to accept one of received answer and on basis of selected one forming a new question and explain where you stuck with your modification. — Zarko, Dec 27 '22 at 00:09
I'm new here and still learning the ropes. I'm sorry for any oversight and I've noted your corrections. Thanks — Nathaniel Ekong, Dec 28 '22 at 09:20
Have a look at this.... https://tex.stackexchange.com/questions/13675/use-graphviz-within-tex — D Duck, Dec 28 '22 at 10:27

score 14 · Accepted Answer · answered Dec 26 '22 at 19:12

An alternative:

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                chains,
                positioning,
                quotes}
\begin{document}
    \begin{tikzpicture}[
node distance = 22mm and 19mm,
  start chain = A going right,
     N/.style = {draw, minimum size=12mm, font=\bfseries},
every edge/.append style = {draw, -Straight Barb, shorten <=2pt, shorten >=3pt},
every edge quotes/.style = {auto, font=\footnotesize, sloped}
                        ]
    \begin{scope}[nodes={N, on chain=A}]
\node   {S};    % A-1
\node   {T};
\node   {L};
\node   {R};
\node   {C};    % A-5
    \end{scope}
\node (A-6) [N, above=of A-3]   {I}; 
\node (A-7) [N, below=of A-3]   {A};
% arrows
\draw   (A-1.north) edge["$\lambda_H$"]   (A-6) 
        (A-1) edge["$(1-\theta)\lambda_T$"] (A-7)
        (A-2) edge["$\alpha\lambda_H$"] (A-6)
        (A-2) edge["$(1-\omega)\lambda_T$"] (A-7)
        (A-3) edge["$\xi$"] (A-7)
        (A-4) edge["$\phi\lambda_H$" ']   (A-6.south)
        (A-4) edge["$(1-\phi)\psi\lambda_T$" '] (A-7)
        (A-5.north west) edge["$\gamma_T$" ']   (A-6)
        (A-5.west) edge["$\gamma_H$" ']    (A-7)
%
        (A-6) edge["$\gamma_I$"]        (A-4.north)
        (A-6.east) edge["$\eta_I\gamma_H$"]  (A-5.north)
%
        ([yshift=+2mm] A-2.east) edge["$\omega\sigma\lambda_T$" ] ([yshift=+2mm] A-3.west)
        ([yshift=-2mm] A-3.west) edge["$\varphi\psi\lambda_T$" '] ([yshift=-2mm] A-2.east)
        (A-4) edge["$\lambda_H$"] (A-3)
%
        (A-1.north) ++ (0,1.6) edge["$\lambda_H$"] (A-1)
        (A-3.north) edge["$\lambda_H$"] ++ (0,1.6)
        (A-4.east) edge["$\lambda_H$"] ++ (1.6,0)
        (A-5.north) edge["$\delta_c+\lambda_H$"] ++ (0,1.6)
        (A-6.north) edge["$\delta_I+\mu_H$"] ++ (0,1.6)
%
        (A-1.south) edge["$\mu_H$"] ++ (0,-1.6)
        (A-7.south) edge["$\delta_A+\mu_H$"] ++ (0,-1.6)
% bending edge
        (A-1.north east) edge[bend  left, "$\theta\lambda_T$"] (A-3.north west)
        (A-3.south east) edge[bend right, "$\lambda_H$"] (A-5.south west)
        ;
    \end{tikzpicture}
\end{document}

Thanks a lot. This was really helpful! – Nathaniel Ekong Dec 26 '22 at 22:29 — Nathaniel Ekong, Dec 26 '22 at 22:29

Daniel N · Answer 2 · 2022-12-27T09:20:41.693

I tried to follow the hand drawing.

The parallel edges are constructed using the control of the leaving and entering angles respectively on the nodes' border.
There are some phantom nodes for the funny arrows; they are introduced using the style cBox.
I wrote down only some of the labels on the arrows; it's a starting point.

The code

\documentclass[11pt, margin=.5cm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta, positioning}
\usetikzlibrary{quotes}
\begin{document}
\tikzset{%
  sqBox/.style={%
    draw, rounded corners,
    minimum width=1.5cm, minimum height=1.5cm,
    outer sep=1ex, font=\bf, scale=1.2
  },
  cBox/.style={%
    minimum width=2pt, minimum height=2pt,
    outer sep=4ex]
  },
  -to/.style={%
    arrows={-Stealth[width=1.5ex, length=1.5ex]}, "$#1$"
  }
}
\begin{tikzpicture}[node distance=3cm and 3cm]
  \begin{scope}[every node/.style={sqBox}]
    \node (L) at (0, 0) {L};
    \node[above=of L] (I) {I};
    \node[below=of L] (A) {A};
    \node[right=of L] (R) {R};
    \node[right=of R] (C) {C};
    \node[left=of L] (T) {T};
    \node[left=of T] (S) {S};
  \end{scope}
  \begin{scope}[every node/.style={cBox}]
    \node[above=of I] (NI) {};
    \node[below=of A] (SA) {};
    \node[below=of C] (SC) {};
    \node[above=of S] (NS) {};
    \node[below=of S] (SS) {};
\node (NWL) at (-3em, 3.5cm) {};

\end{scope}
\path (NS) edge[-to={}] (S);
  \path (S) edge[-to={\lambda_H}] (I) edge[-to={}] (A)
  edge[-to={}] (SS);
  \path (T) edge[-to={}] (I) edge[-to={}] (A)
  (T.20) edge[-to={}] (L.160);
  \path (L) edge[-to={}] (T) edge[-to={}] (A)
  edge[-to={}] (I);
  \path (R) edge[-to={}] (I) edge[-to={}] (L)
  edge[-to={}] (A) edge[-to={}] (C);
  \path (C) edge[-to={}] (I) edge[-to={}] (A);
  \path (I.-65) edge[-to={}] (R.155)
  (I.-5) edge[-to={}] (C.138)
  (I) edge[-to={\delta_I +\mu_H}, swap] (NI);
  \path (A.115) edge[-to={}] (T.-23)
  (A.0) edge[-to={}] (C.225)
  (A) edge[-to={}] (SA);
\draw[preaction={draw, white, line width=4pt}]
  (L) -- (SC.90)
  (SC.90) edge[-to={\lambda_H}, swap] (C);
  \draw[preaction={draw, white, line width=4pt}]
  (S.10) -- (NWL.270)
  (NWL.270) edge[-to={}] (L);
\end{tikzpicture}
\end{document}

Thanks a lot. This was really helpful! – Nathaniel Ekong Dec 26 '22 at 22:28 — Nathaniel Ekong, Dec 26 '22 at 22:28

Zarko · Answer 3 · 2022-12-27T09:06:50.537

As I mentioned in my comment, with editing your question you actually ask new question (please, in future don't doing this; it is not nice that by this you nullify the effort of people who try to help you), hence new answer. It is based on my previous one:

\documentclass[margin=3mm]{standalone}
\usepackage{tikz}
\usetikzlibrary{arrows.meta,
                chains,
                positioning,
                quotes}
\usepackage[low-sup]{subdepth}
\begin{document}
    \begin{tikzpicture}[
node distance = 21mm and 21mm,
  start chain = A going right,
   arr/.style = {-{Straight Barb[angle=60:2pt 3]}, shorten <=3pt, shorten >=3pt},
     N/.style = {draw, minimum size=12mm, font=\bfseries},
every edge/.append style = {arr},
every edge quotes/.style = {auto, font=\footnotesize, sloped},
veqd/.style = {rotate=+90, inner sep=2pt, left},
vequ/.style = {rotate=-90, inner sep=2pt, left}
                        ]
    \begin{scope}[nodes={N, on chain=A}]
\node   {S};    % A-1
\node[below right=-3mm and 19mm of A-1]   {T};
\node   {L};
\node   {R};
\node[above right=-3mm and 19mm of A-4]    {C};    % A-5
    \end{scope}
\node (A-6) [N, above=of A-3]   {I};
\node (A-7) [N, below=of A-3]   {A};
% arrows
\draw   (A-1.north) edge["$\lambda_H$"]   (A-6)
        (A-1.south) edge["$(1-\theta)\lambda_T$"] (A-7.west)
        (A-2) edge["$\alpha\lambda_H$"] (A-6)
        (A-2.south) edge["$(1-\omega)\lambda_T$"] (A-7)
        (A-3) edge["$\xi$" veqd] (A-7)
        (A-4) edge["$\phi\lambda_H$" ']   (A-6.south)
        (A-4) edge["$(1-\phi)\psi\lambda_T$"]   (A-7)
        (A-5.north west) edge["$\gamma^{}_T$" ']   (A-6)
        (A-5.south) edge["$\gamma^{}_H$" ']    (A-7)
%
        (A-6) edge["$\gamma_I$"]        (A-4.north)
        (A-6.east) edge["$\eta_I\gamma^{}_H$"]  (A-5.north)
%
        ([yshift=+2mm] A-2.east) edge["$\omega\sigma\lambda_T$" ] ([yshift=+2mm] A-3.west)
        ([yshift=-2mm] A-3.west) edge["$\varphi\psi\lambda_T$" '] ([yshift=-2mm] A-2.east)
        (A-4) edge["$\lambda_H$" '] (A-3)
% veqd, vequ
        (A-1.north) ++ (0,1.2) edge["$\lambda_H$" veqd] (A-1)
        (A-3.north) edge["$\lambda_H$" vequ] ++ (0,1.2)
        (A-4.east) edge["$\lambda_H$"] ++ (1.2,0)
        (A-5.north) edge["$\delta_c+\lambda_H$" vequ] ++ (0,1.2)
        (A-6.north) edge["$\delta_I+\mu_H$" vequ] ++ (0,1.2)
%
        (A-1.south) edge["$\mu_H$" veqd] ++ (0,-1.2)
        (A-7.south) edge["$\delta_A+\mu_H$" veqd] ++ (0,-1.2)
        ;
% instead of bending edge
\draw[arr] (A-1.east) -| ([xshift=-3mm] A-3.north) node[pos=0.2,above] {$\theta\lambda_T$}; 
\draw[arr] ([xshift=3mm] A-3.north) |- (A-5.west)  node[pos=0.8,above] {$\lambda_H$};
        ;
    \end{tikzpicture}
\end{document}

Sorry about that. I'm new here and still learning the ropes. I've noted your corrections. Thanks. — Nathaniel Ekong, Dec 28 '22 at 09:16

score 3 · Answer 4 · answered Dec 27 '22 at 16:36

I'd suggest tikz-cd (here loaded via the cd library).

While TikZ-CD provides the keys shift left and shift right (used with the arrows between T and L) these usually only work nicely with nodes that do not have a border. Parallel lines between nodes that take the nodes' borders in consideration is not trivial.

Thankfully, the transformation keys xshift and yshift are overloaded and transform the whole arrow (→ shift up etc). But still, for some arrows you will need the ortho keys.

For the arrows between T and A, the angle is just so annoying that it would be easier to select every point on the border manually. Here, I only shift one of the arrows around and let the other be at its natural place. (Meaning that those two arrows are placed asymmetrical but who's going to notice?)

For the connections between S and A as well as C and A I've chose orthogonal connections as well. The other nodes or arrows were in the way.

Code

\documentclass[tikz]{standalone}
\usetikzlibrary{cd}
\tikzcdset{
  tikz/.code=\tikzset{#1},
  hv/.style={to path={-|(\tikztotarget)\tikztonodes}},
  vh/.style={to path={|-(\tikztotarget)\tikztonodes}},
  edge/.style={% something like a pin
    start anchor=#1, to path={--++(#1:1cm)\tikztonodes}},
  ortho/.style args={#1#2:#3:#4}{
    start anchor={[#1shift={#3}]}, end anchor={[#2shift={#4}]}},
  ortho start/.style args={#1:#2}{start anchor={[#1shift={#2}]}},
  ortho   end/.style args={#1:#2}{end anchor={[#1shift={#2}]}},
  shift up/.style={yshift={(#1)*1mm}},  shift up/.default=1,
  shift down/.style={shift up={-(#1)}}, shift down/.default=1,
  shift east/.style={xshift={(#1)*1mm}},  shift east/.default=1,
  shift west/.style={shift east={-(#1)}}, shift west/.default=1,
  */.style=sloped}
\begin{document}
\begin{tikzcd}[
  tikz={down/.style={yshift=+-1cm}},
  >=Latex, arrows=->, arrows={shorten >=+2pt},
  rev/.style={<-, shorten <=+2pt, shorten >=+0pt},
  math mode=false, labels=math mode,
  cells={nodes={minimum size=1cm, draw}},
  column sep=1.5cm, row sep=1.5cm]
& & I
    \ar[edge=north, "\delta_I+\lambda_H"]
    \ar[drr, "\eta_1\lambda_H"'*, shift down]
    \ar[drr, "\lambda_T"*, shift up, rev]
    \ar[dr, "\gamma_I"*, shift east]
    \ar[dr, "\varphi\lambda_H"'*, shift west, rev]
\\
  S \ar[edge=north, "\lambda_H", <-]
    \ar[edge=south, "\lambda_H" ']
    \ar[urr, "\lambda_H"*]
    \ar[drr, "(1-\theta)\lambda_T"' near end, vh, ortho start=x:1.5mm]
    \ar[rr, hv, "\theta\lambda_T" very near start, ortho end=x:-3mm]
& |[down]| T
    \ar[ur, "\alpha\lambda_H"]
    \ar[dr, "(1-\omega)\delta\lambda_T"' *, ortho=xy:-2mm:-2mm]
    \ar[dr, "\gamma_A"*, rev]
    \ar[r, "\omega\sigma\lambda_T", shift left]
    \ar[r, "\gamma_L"', shift right, rev]
& |[down]| L
    \ar[edge=north, "\lambda_H" near end]
    \ar[d, "\xi"]
    \ar[rr, vh, "\lambda_H" very near end, ortho start=x:3mm]
& |[down]| R
    \ar[edge=east, "\mu_H"]
    \ar[l, "\rho\varphi\lambda_T"']
    \ar[dl, "(1-\rho)\varphi\lambda_T" *]
& C \ar[edge=north, "\delta_C+\lambda_H"]
\\
& & A
    \ar[edge=south, "\delta_A+\lambda_H"]
    \ar[urr, "\eta_2\lambda_H"' near start, hv]
    \ar[urr, "\lambda_H" near start, hv, rev, ortho=yx:1.5mm:-1.5mm]
\end{tikzcd}
\end{document}

Output

Thanks a lot. This is really helpful – Nathaniel Ekong Dec 28 '22 at 09:14 — Nathaniel Ekong, Dec 28 '22 at 09:14

I tried drawing this diagram in latex but I'm having trouble with the arrows

4 Answers4

Code

Output

Linked