2

I have been looking at other posts and have modified my code accordingly, but I still can't get it to work. I think there is an issue that has not been addressed in any of the posts that I have found. However, I don't know what the issue is, so I can't make a specific inquiry.

  \begin{tikzpicture}
  \begin{axis}[xmax = 4,ymax = 3,samples = 50]
      \draw[black, smooth, variable=\x] plot (\x,{sqrt(1 - 4(x - \frac{1}{2})^2});
  \end{axis}
  \end{tikzpicture}
  • 1
    Welcome to TeX.SE! If you go this way, the x must be a \x, i.e. \draw[black, smooth, variable=\x] plot (\x,{sqrt(1 - 4*(\x - 1/2)^2});, and you may want to add an appropriate domain. However, since you seem to use pgfplots, use \addplot {sqrt(1-4*(x-1/2)^2)};. – marmot Nov 7 '18 at 18:28
  • Thanks, marmot! Are you referring to the the x within the square root function? – Rafael Vergnaud Nov 7 '18 at 18:29
  • I see. May you clarify what you mean by appropriate domain? – Rafael Vergnaud Nov 7 '18 at 18:30
  • The build is saying the following: You can an axis with empty range (in the y direction) – Rafael Vergnaud Nov 7 '18 at 18:31
  • I have to say, it doesn't come out very nicely. Would you help me make a graph (sorry to be pestering, haha)? – Rafael Vergnaud Nov 7 '18 at 18:33
7

OK, this is too long for a comment. There are several issues:

  • You say variable=\x but one x does not have a backslash.
  • You need to add multiplication signs.
  • You cannot use \frac in an expression that is going to be parsed. \frac is used to typeset fractions.

Altogether, the expression should be (I guess) {sqrt(1 - 4*(x - 1/2)^2}. However, as you are using an axis environment, I think you are loading pgfplots, so I'd suggest

\documentclass[tikz,border=3.14mm]{standalone}
\usepackage{pgfplots}
\pgfplotsset{compat=1.16}
\begin{document}
\begin{tikzpicture}
\begin{axis}[xmax = 4,ymax = 3,samples = 50]
  \addplot[black, smooth,domain=0:1] {sqrt(1 - 4*(x - 1/2)^2};
\end{axis}
\end{tikzpicture}
\end{document}

enter image description here

  • Thank you very much marmot! I appreciate your help. :) – Rafael Vergnaud Nov 7 '18 at 18:40
  • My very last question, which should be brief to answer, is how do I move the plot from the left margin of the pdf to the center of pdf? – Rafael Vergnaud Nov 7 '18 at 18:41
  • @RafaelVergnaud This is due to xmax = 4,ymax = 3,. If you drop these, the plot is centered, and also if you make xmin and so on symmetric around the center. – marmot Nov 7 '18 at 18:46
  • Hey marmot! I mean on the pdf document. I did switch ymax to 4! Adding xmin did not center the plot of the pdf! It is still on the left hand margin of the pdf. If it's a hassle, I'll just leave it. It's no big deal! – Rafael Vergnaud Nov 7 '18 at 18:50
  • @RafaelVergnaud The above document is standalone, so I thought you want to center the curve. If you want to center the plot in a figure in an article document, say, you could use \centering. – marmot Nov 7 '18 at 19:06
3
\documentclass{standalone}
\usepackage{pgfplots}
\begin{document}
\begin{tikzpicture}
\begin{axis}[xmax=10,ymax=10, samples=1000]
  \addplot+[mark=none,samples=200,unbounded coords=jump] {sqrt(x)};
\end{axis}
\end{tikzpicture}
\end{document}

I would suggest to do something like this enter image description here

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.