[Tex/LaTex] Putting tick marks on graph without label using TikZ

graphslabelstikz-pgf

I'm trying to create a piecewise function on a colored background with TikZ that has tick marks on the coordinate axes every 2 units but a grid that intersects the axes every 1 unit. The problem I have is that when I try to add blank spaces for the labels for the tick marks I don't want to show up on the grid, the color background of the blank label cuts off the grid line.

Here is my MWE:

\documentclass[12pt]{article}

\usepackage{amsmath, amssymb}
\usepackage[usenames,dvipsnames,svgnames]{xcolor}

\usepackage{tikz}
\usepackage{tkz-euclide}
\usetkzobj{all}
\usetikzlibrary{positioning,calc}
\usepackage{pgfplots}
\pgfplotsset{soldot/.style={color=black,only marks,mark=*}} 
\pgfplotsset{holdot/.style={color=black,fill=white,only marks,mark=*}}

\usepackage[framemethod=TikZ]{mdframed}
\mdfdefinestyle{ExampleFrame}{%
topline=false,
bottomline=false,
leftline=false,
rightline=false,
innertopmargin=20pt,
innerbottommargin=20pt,
innerrightmargin=20pt,
innerleftmargin=20pt,
backgroundcolor=blue!5!white}

\begin{document}

\begin{mdframed}[style=ExampleFrame]
\begin{center}
\begin{tikzpicture}

\begin{axis}[grid=both,
 axis lines=middle,
 ticklabel style={fill=blue!5!white},
 xmin=-6.5,xmax=6.5,
 xtick={-6,-5,-4,-3,-2,-1,1,2,3,4,5,6},xticklabels={-6, ,-4, ,-2, , ,2, ,4, ,6},
 ymin=-4.5,ymax=4.5,
 ytick={-4,-3,-2,-1,1,2,3,4},yticklabels={-4, ,-2, , ,2, ,4},
 xlabel=\(x\),ylabel=\(y\),
 samples=200]

\addplot[domain=-6:-2,thick] {x+3};
\addplot[domain=-2:1,thick] {2*x+2};
\addplot[domain=1:3,thick] {-2*x+6};
\addplot[domain=3:4,thick] {-4*x+15};
\addplot[domain=4:6,thick] {-1};

\addplot[holdot] coordinates{(-2,1)(3,3)};
\addplot[soldot] coordinates{(-6,-3)(-2,-2)(3,0)(6,-1)};

\end{axis}

\end{tikzpicture}
\end{center}
\end{mdframed}

\end{document}

Which produces this.

output

How do I fix the blank labels so they don't block the grid?

Best Answer

You can simply give only the tick points you want to have a label and make the remaining ones as minor tick so that you don't need to skip the labels that you don't want to have.

One details is that if you have a color spec with the missing second argument such as blue!10 then white is automatically assumed.

Also 200 samples for lines are overkill.

\documentclass{standalone}
\usepackage{pgfplots}
\pgfplotsset{soldot/.style={color=black,only marks,mark=*},
             holdot/.style={color=black,fill=white,only marks,mark=*},
             compat=1.12}
\begin{document}
\begin{tikzpicture}
\begin{axis}[grid=both,
 axis lines=middle,
 ticklabel style={fill=blue!5!white},
 xmin=-6.5,xmax=6.5,
 ymin=-4.5,ymax=4.5,
 xtick={-6,-4,-2,2,4,6},     %<--
 ytick={-4,-2,2,4},          %<--
 minor tick = {-5,-3,...,5}, %<--
 xlabel=\(x\),ylabel=\(y\),
 samples=200]

\addplot[domain=-6:-2,thick] {x+3};
\addplot[domain=-2:1,thick] {2*x+2};
\addplot[domain=1:3,thick] {-2*x+6};
\addplot[domain=3:4,thick] {-4*x+15};
\addplot[domain=4:6,thick] {-1};
\addplot[holdot] coordinates{(-2,1)(3,3)};
\addplot[soldot] coordinates{(-6,-3)(-2,-2)(3,0)(6,-1)};

\end{axis}
\end{tikzpicture}
\end{document}

enter image description here

Related Solutions

[Tex/LaTex] Label variables of equation using tikz without using itemize

Another solution is to use a matrix. This allows you to put the equation in order easily, and then, if you define the cells of the matrix to be nodes, you can then use the positioning library to position your labels relative to those nodes.

(Note that the shorten >= option is used in this code to make the arrows look a bit better, so they don't immediately brush up against the lines of the individual characters. You can modify as you desire.)

\documentclass{article}

\usepackage{tikz}
\usetikzlibrary{matrix}
\usetikzlibrary{positioning}

\begin{document}

\begin{tikzpicture}

    \matrix[name=M1, matrix of nodes, inner sep=0pt, column sep=0pt]{
      \node (Y1) {Y}; & \node (equals) {=}; & \node (Y2) {Y}; & ( & \node (X) {X,}; & \node (Z) {Z,}; & \node (W) {W;}; & \node (A) {A}; & ) \\
    };

    \node (Output) [left=2.5em of Y1] {Output};
    \node (VariableZ) [above=2.5em of Z] {Variable Z};
    \node (VariableW) [below=2.5em of W] {Variable W};
    \node (VariableX) [left=2em of VariableZ] {Variable X};
    \node (ParameterA) [right=2em of VariableZ] {Parameter A};

    \draw[->] (Output) -- (Y1);
    \draw[->, shorten >=0.1em] (VariableZ) -- (Z);
    \draw[->, shorten >=0.2em] (VariableX) -- (X.north);
    \draw[->, shorten >=0.1em] (ParameterA) -- (A.north);
    \draw[->] (VariableW) -- (W);


\end{tikzpicture}

\end{document}

enter image description here

[Tex/LaTex] Tikz and exponential style tick label

This is not correct. It is, rather, a cleaner hack which does not fail with an error on compilation, as the code in the question does.

Following the example on page 805 of the manual, we define \mytypesetter as follows:

\def\mytypesetter#1{% page 805
  \tikzset{%
    /pgf/number format/.cd,
    sci,
    sci generic={mantissa sep=,exponent={0^{##1}}}%
  }%
  \pgfmathprintnumber{#1}%
}

Since in this case the mantissa is always equal to 1, setting mantissa sep to an empty value and typesetting to exponent as 0^{<value>} rather than 10^{<value>} should give the result we want.

This is obviously not a good solution, but only a hack, because this is far from semantic mark-up. Indeed, it mixes format and content in an especially horrible way.

We can, however, then say

      tick typesetter/.code=\mytypesetter{##1},

to produce the required output, if I've understood the desiderata correctly.

If you prefer to configure this all in the one place, you can do so but you must distinguish between the first argument being passed to tick typesetter and the first argument being passed to /pgf/number format/sci generic. You do not want to pass the former to the latter else you will end up with the entire number formatted in the exponent, in addition to the mantissa part and the separator preceding it.

  y axis={
    logarithmic,
    ticks and grid={
      step=1,
      minor steps between steps=8,
      tick typesetter/.code={%
        \tikzset{%
          /pgf/number format/.cd,
          sci,
          sci generic={mantissa sep=,exponent={0^{####1}}}%
        }%
        \pgfmathprintnumber{##1}
      }
    },
  },

I would tend not to do this as I find this much harder to read than the first version which splits out the code formatting the number from the processing of the number in the axis definition. But the second version produces the same output if you prefer it for some reason.

Complete code:

\documentclass[tikz,border=10pt]{standalone}
\usetikzlibrary{datavisualization,datavisualization.formats.functions}
\def\mytypesetter#1{% page 805
  \tikzset{%
    /pgf/number format/.cd,
    sci,
    sci generic={mantissa sep=,exponent={0^{##1}}}%
  }%
  \pgfmathprintnumber{#1}%
}

\begin{document}
\begin{tikzpicture}
  \datavisualization [
  scientific axes,
  all axes={length=6cm},
  x axis={
    ticks and grid={
      step=2,
      minor steps between steps=1
    },
    include value={0,20},
  },
  y axis={
    logarithmic,
    ticks and grid={
      step=1,
      minor steps between steps=8,
      tick typesetter/.code=\mytypesetter{##1},
    },
  },
  visualize as line
  ]
  data[separator=\space] {
    x y
    0 1E1
    5 1E2
    10 1E3
    15 1E4
    20 1E5
  }
  ;
\end{tikzpicture}
\end{document}

Best Answer

Related Solutions

[Tex/LaTex] Label variables of equation using tikz without using itemize

[Tex/LaTex] Tikz and exponential style tick label

Related Question